The South Bay region of San Diego County is bounded by Downtown San Diego to the north, the Pacific Ocean to the west, the international border with Mexico to the south, and the Otay Lakes to the east. The largest city in this area is Chula Vista, which is the second largest in the county behind San Diego.
- Chula Vista - The largest city in the region
- Coronado - A scenic island community located across the San Diego Bay from Downtown San Diego
- Imperial Beach - A small beachside city at the southern end of the bay
- National City - A small city just south of Downtown San Diego that is home to ship ports
- San Diego - Most of San Diego lies to the north of the South Bay area, but San Diego does encompass San Ysidro, a community situated on the USA-Mexican border which is also the major crossing between the USA and Tijuana, Mexico.
I-5 and I-805 run north-south through the area, down to San Ysidro, where I-5 proceeds all the way to the border. You can drive to the border crossing and then continue driving through, or park at one of the lots and walk through. Parking at one of the lots costs about $4-9 a day. Traffic is pretty heavy coming up from Mexico.
The San Diego Trolley  Blue Line service runs south from Downtown through National City and Chula Vista down to San Ysidro. Standard, one-way fares run $1.25-$3 depending on how far you travel. Day passes are $5, and there are 2, 3 and 4 day passes available as well.
- The Hotel del Coronado in Coronado is a beautiful architectural masterpiece.
- The Chula Vista Nature Center in Chula Vista is a quiet and rather scenic attraction, situated in the midst of a wetland under restoration.
- Silver Strand State Beach, on SR-75 between Coronado and Imperial Beach, about 5 miles south of Coronado +1 619 435-5184, . Daily 8AM-7PM. Located on the Silver Strand, this is an excellent beach to swim or surf at. RV camping and fishing are allowed here.
- Bayshore Bikeway. A 25-mile bikeway that is a very popular and scenic route. The level of difficulty is low as there are no major hills on this route, and it is also one of the safest bike routes. The 2.5-hour ride takes cyclists along the bay past golf courses, lagoons, piers and numerous places to stop for a rest and a drink of water such as Pepper Park and Glorietta Bay Park to name a few. The route also features a nine-mile stretch that follows the former Coronado Branch of the San Diego and Arizona Eastern Railroad.
- Tijuana Estuary, 301 Caspian Way (in Imperial Beach), +1 619 575-3613 . Park: Sunrise-Sunset. Visitor Center: W-Su 10AM-5PM. A small coastal estuary located south of Imperial Beach and one of the few salt marshes remaining in Southern California. Next to the estuary at the USA-Mexico border is Border Field State Park, which covers the extreme southwestern corner of the United States, where the USA-Mexico border meets the ocean. Border Patrol officials keep a close eye on this area. $5 per vehicle.
- The U.S. Open Sandcastle Competition  takes place every July in Imperial Beach, and is a great chance to see professional sand castle crafters at work.
Because San Ysidro is located near the border with Mexico, the crime levels are higher than normal. Use common sense, and do not get involved in any situation that could have anything gang activity/drugs written on it.