San Diego  is a beautiful city on the Southern California seacoast known for its ideal climate, miles of beaches, and its location on the Mexican border, right across from Tijuana. It has a rich heritage built around sailing and is home to the Pacific Fleet of the United States Navy. It is also well known for its part in the wildlife conservation movement, being home to a SeaWorld theme park and the "world-famous" San Diego Zoo and Wild Animal Park. San Diego is an excellent place to escape from the hustle and bustle of nearby Los Angeles.
Save for bureaucratic purposes, San Diego really doesn't have any clearly defined "regions". For the average traveler or citizen of San Diego, such boundaries are often meaningless. Many of the city's most frequently-visited neighborhoods are quite unique, even from those situated right next door, and much of San Diego is suburban neighborhoods which offer little to the traveler. With this in mind, listed here is a break down of the neighborhoods of real interest to the average traveler:
The area has long been inhabited by the native Kumeyaay people (also known as the Diegueño by the later Spanish settlers), who lived off the land and had created a proud culture. The first time a European visited the region was in 1542, when Portuguese explorer Juan Rodriguez Cabrillo, sailing under the Spanish Flag, claimed the bay for the Spanish Empire and named the site San Miguel.
In November of 1602, Sebastián Vizcaíno was sent to map the California coast. Arriving with his flagship "San Diego", Vizcaíno surveyed the harbor and what is now Mission Bay and Point Loma, renaming the area for the Spanish Catholic Saint St. Didacus (More commonly known as San Diego).
San Diego was established in 1769 as the first Spanish mission in California, at the present site of Old Town. However due to the poor nature of soils in the Old Town area, the mission was eventually relocated about five miles up river in Mission Valley.
In the 19th century, San Diego passed from Spanish to Mexican to American hands. In 1850, a few years after the United States gained control of California, San Diego was officially designated a city. But with much of the westward expansion to California centered on the gold rush and San Francisco, American influences were slow to come to San Diego. But eventually they did, and in the later decades of the 19th century the railroad came to San Diego, resulting in further growth of the city and the establishment of Downtown and its surrounding neighborhoods.
The U.S. Navy discovered San Diego in the early 20th century, and constructed a coaling station on Point Loma in 1907. Ten years later, the Naval Air Station on Coronado island was established, and in later years the Navy would take on an increasingly important role in the city's economy. Today San Diego is home to the Navy's Pacific Fleet, and is a favorite leave location for sailors.
In recent decades, growth in San Diego has exploded, with many corporations moving their headquarters here and a huge influx of residents. Today it's a favorite destination for retirees and tourists.
The San Diego area can be an incredible place to visit almost any time of the year. With coastal temperatures around 75 degrees (24°C) most of the time, the weather is ideal. The climate of Southern California is rather complex, however, and temperatures change rapidly as one travels from the coast eastward. In the summer during the day, the temperature might increase as much as one degree Fahrenheit for each mile going east. In the winter, especially at night, eastern areas are usually relatively cooler. Some valleys and other areas have significantly different weather due to terrain and other factors; this is often referred to as "microclimates". September is usually the hottest month of the year in the daytime, though by then, nights are slightly cooler than in August. Along the beach during the warmer half of the year, it can get surprisingly cool after dark, even when it's not too cold a short distance inland.
During the late summer and fall, Santa Ana events - a reversal of the usual climate conditions, when moist air blows inland from the coast - sometimes occur. Milder Santa Anas can result in excellent dry air conditions, but powerful ones can last days on end; significantly rising temperatures, creating tremendous fire danger, and can make being outdoors a horrendous experience.
San Diego International Airport (IATA: SAN) is less than 10 minutes from downtown San Diego. The descent into the airport if from the east is remarkably close to downtown buildings, which can be a bit alarming for first-time visitors. It is served by legacy carriers such as American Airlines, Delta Airlines, Continental Airlines, Northwest Airlines, United Airlines, and US Airways. Low fare carriers include ExpressJet, JetBlue, Southwest Airlines, Skybus Airlines, and most other major low-fare carriers. Beware that even discounted coach airfares between San Diego and Los Angeles (about 120 miles/190 km) can cost nearly as much a trip to the east coast. (This will usually be greatly discounted or even free for connecting flights if it's part of the overall routing, but you must leave LAX within four hours for domestic flights or 24 hours international.) The only international flights from SAN go to Mexico and Canada; visitors from other countries would probably travel through Los Angeles or San Francisco. Fixed point ground transportation between LAX and San Diego is extremely limited, while taxi/van service is more costly than flying (except for groups of about six or more). If arriving at LAX, always know the method and cost of how you're getting to San Diego in advance.
There are a number of airport shuttle companies that handle transportation to and from the airport. They cost around $15 per person. Metro bus #992 The Flyer ($2.25) travels 10 minutes to downtown San Diego, and connects to the Coaster commuter train, the Trolley, and the Amtrak station.
Driving out of the airport can be a little confusing. Unless you're headed to Point Loma or Harbor Island, you want to go east towards downtown. The first left turn after the airport is Laurel Street to Balboa Park. The second one is Grape Street, and this has access to all the freeways. Caution: Do not run the red light, or an automated camera will issue a citation of at least $340! For the I-5 north freeway, stay in the left lane of Grape St., or the right lane for I-5 south. The 163 north and 94 east freeways are via I-5 south. Remain in the right freeway lanes for the 163 and 94 as these exits will come very quickly. If going downtown, Petco Park (baseball), Seaport Village, or the Convention Center, just stay on Harbor Drive from the airport. However, for the east side of downtown (except at rush hour), it may be easier to use the 10th Ave. exit from I-5 south, which is the furthest right lane of the 163 freeway exit.
McClellan-Palomar Airport (IATA: CLD) is the other commercial passenger airport in San Diego County. Commercial operations are limited to two commuter airlines, United Express and US Airways Express, which provide service from Los Angeles and Phoenix. The airport is located in the city of Carlsbad, about 35 miles north of downtown San Diego. Exiting the airport by car, turn right onto Palomar Airport Road and proceed onto Interstate 5 southbound to reach San Diego proper. There is an AVIS car rental facility on-site.
Private pilots will prefer the nearby general aviation airports, Montgomery Field (ICAO: KMYF) in Clairemont Mesa, Gillespie Field (ICAO: KSEE) in El Cajon, or Brown Field (ICAO: KSDM) east of San Ysidro. Some air taxi and air charter firms offer specials to the San Diego area from local airports, including from many smaller Los Angeles airports and from the San Luis Obispo area.
San Diego's Amtrak  station is the historic Santa Fe Depot, located in downtown at 1050 Kettner Blvd. The station is the southern terminus of Amtrak's frequent Pacific Surfliner  route, which runs north to Los Angeles and San Luis Obispo. The depot is within walking distance of downtown hotels and situated next to San Diego Bay. Shuttles offer service between the train depot and San Diego International Airport.
There is also a secondary rail station located at the Old Town San Diego Historic Park; it is used mainly for travel within San Diego County, although Amtrak also serves it occasionally.
Other rail services include the COASTER , a commuter train that runs north from downtown along the coast into northern San Diego County all the way to Oceanside where it meets the Metrolink rail service from Los Angeles. Service is mostly limited to the weekday rush hours, with limited service on the weekends. Fares are based on how far you ride; a one-way fare will be in the range of $4-$5.50. Tickets must be purchased from the ticket vending machines located at each station.
San Diego is easily accessible by car using any one of the three major interstate roadways, the 5, 8, and 15 Freeways.
Additionally, there are numerous other freeways that crisscross the county, making access to most places in San Diego relatively easy. However, be advised that traffic is frequently congested during daytime hours.
Current cruise services only offer excursions departing from San Diego to Baja Mexico and Los Angeles. These include dinner cruises, three-day gambling cruises and 'party excursions' to the Mexican coastal ports of Baja.
Generally speaking, San Diego's transportation infrastructure is much more efficient than that of Los Angeles; both automobiles and public transport are almost equally efficient in getting from one place to the next.
The San Diego metropolitan area is large and sprawling. If possible, car travel is the most efficient way of navigating the city and county. However, in the beach communities parking can often be in short supply.
By public transit
The Metropolitan Transit System (MTS)  operates bus service to almost all parts of the county, although service in many areas is sparse and infrequent. The weakest points in the transit system are suburb-to-suburb travel and poor links between the individual coastal communities, both of which often require long trips to one of the transit hubs. If you will be mainly in the areas around downtown, the bus may be suitable, but as a rule San Diego has inadequate mass transport for tourists or residents. The fare is $2 for local/neighborhood routes, $2.25 for urban routes, and $2.50 for express routes. Transfers are not available. Day passes (which also include rides on the Trolley) runs at $5. All downtown buses intersect with Broadway Street at some point. During the day all kinds of people will be taking the bus. At nights some people might feel a little less comfortable, but generally not unsafe on the main parts of downtown. The MTS has offices in downtown, on Broadway Street.
Trolley (light rail)
The San Diego Trolley  is a light rail system operated by the MTS which mainly serves tourists and people living in the southern and eastern parts of the city that need to get to downtown areas. There are three trolley lines: blue, green, and orange. The Blue Line operates from the US-Mexico border at San Ysidro and runs to Old Town, via Chula Vista, National City, and Downtown. The Green Line travels from Old Town east to Santee, via Mission Valley and SDSU. The Orange Line connects the eastern cities of El Cajon and La Mesa with Downtown (generally not as usable for tourists except for getting around parts of downtown).
Standard one-way fares run from $1.25 to $3 depending on how far you travel. Day passes (which include bus service) run at $5, and there are 2, 3 and 4 day passes available. Tickets have to be purchased from the vending machines at the station before you board the train. There's no formal system to check if you've purchased a ticket, but there are trolley guards that may come around and ask to see your ticket, and the fine is normally around $120 for not having a ticket.
Like much of California, English is the predominant language with Spanish widely spoken. Store signs are commonly written in both languages and most businesses have bilingual employees that speak both English and Spanish. Tagalog is also commonly spoken in San Diego by the city's large Filipino population.
These are just the most significant sights. More specific information may be found under the Districts header above.
Universities in the area:
San Diego is a major technology and defense hub of California and the United States. Major industries include defense, telecommunications, technology, biotechnology, computers and scientific research. With five major military bases located within fifty miles of San Diego, defense related services and support are a key part of San Diego's prosperity.
San Diego is dotted with major shopping centers and upscale boutiques catering to nearly every style of dress and expression.
The district sections of San Diego offer more details on local places to eat. Food representing almost every world cuisine can be found somewhere in the city, including Mexican, Moroccan,Ethiopian, Thai, Vietnamese, Afghan, Persian, Chinese, Japanese, Spanish, French, British, Italian and Cuban cuisine.
Like other large metropolitan areas, San Diego carries a wide variety of national and international food. Major restaurant chains are found almost in every district.
Bars and clubs can stay open past 2:00am but are not permitted to sell alcohol after this time. A medium-sized beer generally costs 4-5 USD in a restaurant.
San Diego is considered to be one of the safest cities in California. Though crime is present, violent crime is on an overall decrease, but property crime still exists. One should use the same precautions as you would in any large metropolitan area. Avoid walking in Southeast San Diego or Barrio Logan (near or under the Coronado bridge) at night. If you do or must, avoid walking down dark alleyways or approaching unknown people. Most people do not encounter any problems if they avoid buying illegal drugs or prostitution. In addition, gangs are not as present as they are in Los Angeles, but they still exist.
In an emergency (immediate danger to loss of life or limb), call 911. Be aware that if you call from a cell phone, 911 calls are currently directed to the California Highway Patrol, which can result in delays in contacting city police. (911 calls made from land-line telephones are directed to the appropriate local agency.)
In many cases when within the city limits it may be more appropriate to directly dial the San Diego non-emergency number, (619) 531-2000. For example, to report a crime in progress when you are not in direct danger, it is probably best to call the San Diego Police (or other local municipality) directly.
San Diego is served by a professional police force  as well as a county sheriff department; additional protection is offered on the major highways by the California Highway Patrol (CHP). To report a non-emergency within city limits, call (619) 531-2000.
The city of San Diego fire department is a top-rated service offering fire protection, emergency medical care, hazardous waste cleanup, and search and rescue functions. If you dial 911 for an emergency it is guaranteed that the first responders will be the San Diego Fire Department. Urban brush fires are always a risk during the summer and fall, but rarely affect tourists.
There are numerous public and private hospitals in San Diego. These range from state funded institutions such as UCSD-Hillcrest and Thorton to private, world-renowned hospitals of Scripps La Jolla and the Children's Hospital. Non-profit Sharp Health Care also owns several hospitals, and has many "Urgent Care" centers for non-so-serious injuries such as a broken arm (daytime and early evening only). First-rate, world-class medical care can be found at any of these hospitals, as well as interpreters for more than a dozen languages.
San Diego is home to some of the most cutting edge health research in the country. The University of California, San Diego Medical Center is known for it's world class research. Some residents head to Mexico for cheaper health care, but this can be risky, and it would be more wise to use San Diego hospitals and clinics. Many of the institutions have doctors of all nationalities so language may not be a problem for some whose English skills may not be so good.
Rip currents are notorious in San Diego for their strength and sudden appearance. Do not go out in the water without lifeguard supervision or at night. At La Jolla Shores, rip currents can be so strong that people standing (not swimming) in waist-deep water have been pulled out over their heads -- sometimes with deadly results (especially for non-swimmers). Except for sunbathing, avoid low tide like the plague at this beach. (This means the largest of the two daily tide cycles. Check newspaper weather page for Scripps Pier, or view the Weather Channel.) All of the major beaches have lifeguards on duty in the summertime, with only the more popular beaches having lifeguards year round.
Many of the ocean cliffs are made of a compressed sandstone and are prone to collapse, especially in rainy weather. Follow all signs. Heavy rain may cause rising bacteria and chemical levels in the ocean waters. Care should be taken to read the newspapers or call the county health office to see if the water is safe for swimming. Generally most people keep away from the beaches for 24 to 72 hours after rain.
Access to the beaches is safely made by using any of the public stairways provided; they are well maintained (except at Black's Beach) and free. The stairs at Black's Beach are in disrepair, and at one's own risk. Wear sturdy shoes, and don't try unless you are in very good physical condition and able to climb the 300 ft. (100m) back from the beach. Beware of the false trails going down the cliffs, as every year a few people get stuck (or worse!). Take a little time to familiarize yourself with the area and observe where others are going. Though a long walk, you can also get in from the north via Torrey Pines State Beach. (Parking $8 in the lot or free along the highway.) High tide will cut off this route, so plan ahead.
The bridge that connects Torrey Pines (north of Black's Beach) with Del Mar (former Hwy US 101) is old and in need of repair. Avoid walking directly underneath, as pieces of concrete occasionally fall off. It's still considered safe enough to drive over for now. If concerned, access this area from the south via I-5 and Genesee Avenue (exit #29) which soon becomes N. Torrey Pines Rd. Always supervise children very closely at places such as Sunset Cliffs and the Torrey Pines Glider Port above Black's Beach. It may be necessary to hold their hand at all times. If you have unruly kids, don't go there.
Thefts do occur at the beach, and can ruin a perfectly wonderful day. Do not leave any purses or other personal items of value alone on the beach or in an open car. Vehicle burglaries are more prevalent in most beach communities, and take place in broad daylight. If possible, do not leave anything of value in your car even when locked. Most kayak and beach rental shops offer safe boxes free of charge, and will store your valuables while renting.
In addition, take caution when around certain beach areas, as you may wonder (inadvertently) on to a military instillation, where security is tight and beaches are either reserved for military patrons and their families or training centers.
Smoking is banned in all restaurants, bars, public offices, and other places by order of California law. There is a county wide ban on smoking in all state parks and there are city wide bans in San Diego, Del Mar, and Solana Beach that forbids smoking on public parks and beaches. El Cajon bans ALL outdoor smoking in public places. A new law enacted in January of 2007 prohibits smoking within 25 feet of any MTS transit station or bus stop. Beginning July 1, 2007 those caught smoking near transit facilities will face a fine of $75.
The most common area code for San Diego Metropolitan area, including downtown, the southbay and the eastern suburbs is 619. North of I-8/Mission Valley uses 858, and the far northern suburbs (Escondido, Oceanside, etc.) use 760. Be sure to look when dialing a phone number that may be in a different area code, and most public telephones and hotel phones have the area code next to the phone number on the actual device.
In the area of the Westin Hotel, there is free WiFi. The SSID is "turbonet".
In the Little Italy area, there is free WiFi.
San Diego is probably the best city in America for making a quick trip to Mexico. Tijuana, San Diego's twin city across the border, is only a short trip by car. Trolley service is also available from downtown San Diego to the US-Mexican border. Avoid driving hassles and long waits when returning by parking in pay lots near the border and walking across. Taxis, buses, and private car hires are all available. if traveling to Tijuana Airport, Mexican airline Volaris operates a bus service between that airport and San Diego's Santa Fe Train Depot.
For a delightful, low-key alternative, drive 60 minutes on the American side to the small border crossing of Tecate (home of the Tecate brewery). It's a short walk to the town square. Coming back, there are typically only a couple of people in line at the pedestrian crossing. You can easily combine a trip to the train museum in nearby Campo with a quick trip across the border for lunch!
Julian is the largest and most popular mountain community in San Diego County. Also, nearby is Cuyamaca Rancho State Park and Palomar Mountain which has a large observatory. Beware, on hot summer days, the mountains are actually warmer than the city (as they're next to the desert).
The greater San Diego County has a lot of smaller, more private beaches, and some great small towns to stay in and explore. Further east, the Imperial Valley and the California Desert give a change of scenery.
It's also relatively easy to get up to Los Angeles and other points in Southern California. The 5 freeway extends through Oregon and Washington the Canadian border. Although slower, Highway 1 (Pacific Coast Highway in most of Southern California) and the 101 Freeway, through the Central Coast, Monterey Bay, and the San Francisco Bay Area, make for more of a pleasant and fruitful trip.
There are no boats to Catalina Island (Avalon) within San Diego County. You'll have to go about 8 miles into neighboring Orange County to the pier at Dana Point. By car, take I-5 to exit #79 Pacific Coast Hwy 1. (make reservations)
Temecula Wine Country. Located about 60 minutes northeast of San Diego, there are about 20 vineyards (with tasting rooms) located fairly close to each other. This trip makes a good day trip from San Diego. One hour further is the mountain resort of Idyllwild which features shopping and outdoor activities in an alpine forest.