A Mexican peninsula extending into the Pacific Ocean from the south end of the U.S. state of California, Baja California provides some of Mexico's most dramatic sea and landscapes. This includes everything from vast and remote deserts, dormant volcanoes and wonderful old mission towns. The first political capital of "old California" is found here as well as many remnants of the colonial past, (Alta California or Upper California roughly translates into the modern day US state and was settled later). Camping and hiking opportunities are plentiful, and much of the region is sparsely or even unpopulated. The "Baja" is also home to world class surfing, sailing and deep sea fishing destinations. Lastly, traditionally the peninsula has provided south-of-the-border fun for youthful miscreants from the USA in both the border region to the north and more recently at the far end of the peninsula in the resort towns of Los Cabos. The Baja peninsula is one of the longest in the world and offers an interesting mix of cultures with a wonderful combination of Latino, Hispanic, pre-Hispanic and even some Anglo influences. It varies greatly even from the Mexican "mainland" with its own lifestyle and identity within Mexico.
Road Trips (routes)
Much of Baja's coastline is composed of beautiful beaches. In general, the Sea of Cortez side is much less exposed to the open sea as the western shore. Therefore, it tends to be less rocky and more sandy than the Pacific side. The Pacific side is ideal for surfing whereas the eastern shoreline is potentially more inviting to beach-goers. The central and southern sections are home to remote and extremely desolate deserts which include substantial mountains, large sand dunes, towering cacti and dormant volcanoes projecting an almost alien landscape similar to parts of the American Southwest. Into A Desert Place is non-fiction account of a circumnavigation of the Baja by foot.
As in most of Mexico some Spanish can go a long way and is greatly appreciated. Many locals have been to or worked in the United States, so the knowledge of English is high, particularly in the north along the border and in the tourist towns of Los Cabos and La Paz. Some Mexican school children also receive English education in schools.
Border Crossings Interstate 8 (I-8) is the main east-west highway along the American side of the border between San Diego and Casa Grande, AZ where to joins into I-10 to continue east to El Paso via Tucson and Las Cruces. Along the Mexican side, Mexico Federal Hwy 2 (MX-2) runs parallel between Tijuana and Cd Juarez via Nogales. The crossing points are:
Mexico Federal Hwy (MX-1/1D) goes north-south along the length of the Baja California Peninsula from Tijuana down to San Jose del Cabo while MX-15/15D goes south to Mexico City via Cualican, Mazatlan, Tepic and Guadalajara from MX-2 in Nogales while MX-45/45D goes south to Mexico City via Chihuahua, Torreon, Zacatecas, Morelia, and Queretaro from MX-2 in Cd Juarez.
Most tourists who visit Baja fly directly to Los Cabos (SJD). There are international airports located in Tijuana and Mexicali, but if coming from the US it will be easier and cheaper to fly to San Diego or Los Angeles (nearest US airports to Tijuana and Mexicali) and drive or take the bus in (be sure you're allowed to take your rental car to Mexico).
Baja is a popular destination for private pilots. There are general aviation airports along the peninsula, most with decent facilities and fuel. Procedures for entering Baja should be checked regularly, as they may change. Flying clubs may not allow aircraft rentals to travel to Baja.
Long distance bus services in Mexico are superior to that of the United States, with modern, comfortable buses for long-distance travel. The primary carrier traveling up and down the Baja California peninsula is ABC (Autobuses de Baja California) while Grupo Estrella Blanca connects Tijuana and Mexicali with other cities on the Mexican mainland (via Hwy 2 and 15). Greyhound travels east and west along the American side of the border, where the roads are better and the vehicles travel quicker such as travel between San Diego & El Paso or anywhere in between. One must make sure (s)he have the proper travel documents to cross in the US to travel along the US side of the border.
There are no regularly scheduled trains entering Baja from the USA or from other places in Mexico, but Amtrak has service to San Diego from Los Angeles, from there you can easily cross to Tijuana, and take onward buses to elsewhere in the peninsula.
Many people travel from the USA and Canada to Baja by car, RV, or motorcycle. The Transpeninsular Highway is well maintained, but it is very narrow and winding in many places. The middle section is the most remote and desolate. Driving it alone can be a serious challenge and driving at night is not recommended. Horses and cows, in addition to other wildlife often cross the road or stray right into the road! This is a serious hazard. The other major hazard are the driving habits of Mexican nationals, who can be very reckless at times. Trucks in particular are very dangerous and be alert whenever anyone is passing, or head on collisions may result. While well kept and clean and friendly, the Pemex stations are not always open or may run out of gas. ALWAYS drive on a full tank of gas in the Baja whenever possible! There are numerous checkpoints manned by the Mexican Army along the highway. It is mandatory to stop. The soldiers are only interested in illegal drugs or guns. They are very professional in general. They have the right to search your car or RV and ask what your destination is. Always have your Mexican green tourist card and passport ready. Once they have determined you are not a drug smuggler, you will be on your way. They are manned 24 hours a day.
Note that Mexican auto liability insurance is now required throughout the country.
There is a slow but steady trickle of travelers riding their bicycles in Baja. On the Transpeninsular Highway this is fairly straightforward. It's easy to find the way, and in populated areas small shops or restaurants can be expected almost daily, and there are plenty of good wild campsites, and RV parks. A traditional touring, or hybrid bike is an excellent choice for the Transpeninsular. The middle stretch of the road and the peninsula present regions that are both very mountainous and desolate. Riding a bike on the numerous other roads would certainly require a mountain bike, and would be preferable with a support vehicle due to the difficulty in acquiring basic supplies (the main concern being water) and the difficulty carrying baggage on rough roads. Trying to travel by bike unsupported off the Transpeninsular is for those who don't distinguish between masochism and adventure. Either on or off the Transpeninsular, good quality tires, lots of patches, spare tubes, and other puncture resistant measures are important, due to the large numbers of vicious thorns. Drivers on the Transpeninsular Highway are often very reckless, however most drivers treat cyclists with more respect (perhaps due to their novelty) then cyclists get elsewhere in North America. If one chooses to bike in what is normally a very hot climate and incredibly remote region at times, the whole endeavor should only be undertaken with much prudence and planning.
A number of blogs with useful information for cyclists can be found by internet searching. This site is one created specifically as a guide for cycling the Baja California and contains information on services, riding conditions and safety hazards.
Most of the people you meet will tell you that you are crazy for hitching, but pick you up none the less. In-town hitching is much more widely accepted and you will often see trucks filled with people in the back. The biggest problem with hitching across Baja is that the amount of traffic depends heavily on the tourist season. Surfers are a good bet for a ride, at least across Baja north. Expect that traversing the entire peninsula will take you between 3 1/2 - 4 days, less if in the tourist season. Be adamant about not carrying drugs when your driver asks if you are caring any. Your average wait is about an hour and a half, but do not be surprised if you wait up to four.
Mexicali's Chinese restaurants are well-known.
Beer is often sold by the case, from local distributors. Keep the empties - the deposit makes up a large portion of the price, and the bottles are not just recycled - they're washed out and reused!
Locals distill their own tequilas from the blue agave plant (not a cactus). One common drink is Tequila and Sangrita (not Sangria), a spiced fruit punch drunk in shots.
The Santo Thomas region south of Ensenada is known for its wineries.
Ferries are available from La Paz to mainland Mexico. They are not cheap!
Scofflaws - gringos getting drunk, using drugs or visiting prostitutes - are the most likely to experience Mexico's legal system. Most laws in Baja, though less frequently enforced, carry more severe penalties than they do in the United States.
Bandits (Bandidos) are more urban legend than reality, though there are occasional reports of robberies on remote highways. Crime is more common in Northern Baja, especially between Tijuana and Ensenada. Since June of 2007, about a half-dozen robberies and carjackings that targeted U.S. surfers en route to camping spots along the 1250 km long Baja California peninsula have occurred, according to unconfirmed tallies reported via the Internet."Troubling Sign in Baja - San Diego Union Tribune" 
Violent crimes are rare between San Quintín and Cabos San Lucas, but due to isolation and lack of development this portion of Baja has a different set of risks. This portion of the peninsular highway is extremely remote and traveling in a well fueled reliable vehicle is essential. Gas stations often run out of gas or are closed, so never risk driving while low on fuel. Driving at night is not recommended. One of several reasons is due to the risk of livestock and wild horses in the roads. Another is to avoid other intoxicated drivers. Mexican drivers are often overly aggressive while overtaking and the Baja's main highway Number "1" is marked with literally hundreds of crosses marking spots where drivers met their untimely end. Car insurance, though expensive, is highly recommended.
Drug Dealers, mostly international, use the remote areas of Baja for operations; most tourists are unlikely to encounter them. However, because of this problem there are several checkpoints maintained by the Mexican military along the highway. The inter-peninsular border is a particularly sensitive area and expect to ask for your tourist card and or passport when crossing. Soldiers and officials are usually very friendly and courteous provided your full cooperation. Never run through military checkpoints as guards are armed and have the right to shoot! Drug smuggling, any form of firearm (illegal in Mexico) and fruits and vegetables are their main concerns. With that said never agree to carry anything for anybody (you don't know or barely know), especially if promises of a hefty compensation were offered, within Mexico or to carry across into the U.S. If you're caught carrying drugs, firearms, or any contraband you WILL be going to jail despite the fact that they weren't yours or you didn't know what you were carrying. Ignore anybody approaching to sell you drugs. It can be a set up by an informant disguised as a dealer. Buy the drugs from this informant and then be shaken down by an officer (partner in crime w/ the first dealer) down the street for a hefty "fine" or go to jail.
Mexico is a traditional Catholic country, therefore nude (and for women, topless) sunbathing is illegal in Mexico - while you often will get away with it on remote beaches, many of the locals strongly disapprove, and there are reports of large fines.
The Water in restaurants is generally bottled and purified. Do not drink tap water as in most of Mexico.
Some if not all USA cell phone services can be set to call USA numbers just like any other long distance call. High roaming charges may apply. See your cell phone service provider for details. Portions of the Baja include some of the most remote parts of North America so service will only apply to major cities.
To call USA numbers from a local pay phone or local private phone, use a calling card. Calling the USA via numbers suggested on payphones are outrageously high. All Mexican pay phones require a pre-paid plastic phone card. For longer term travels, SIM cards can be purchased cheaply that allows various plans for calls to both Mexico and the United States. It is virtually impossible to call 800 numbers from the Baja; therefore it is prudent to carry a non-800 number alternative. Directory assistance calls are rapaciously expensive, so jot all important numbers in advance of your trip.WikiPedia:Baja California Peninsula Dmoz:North_America/Mexico/States/Baja_California/ World66:northamerica/mexico/bajacalifornia