Anza-Borrego Desert State Park
Anza-Borrego Desert State Park  in southern California is the largest state park in the state and the second largest in the United States (after Adirondack State Park in New York). The park is located on the eastern side of San Diego County, with portions extending east into Imperial County and north into Riverside County. It is about a two-hour drive from San Diego, Riverside and Palm Springs. The park is named after Spanish explorer Juan Bautista de Anza and the Spanish word borrego, or bighorn sheep.
The park consists of 500 miles of dirt roads, and miles and miles of hiking trails. Additionally, the park features views, washes, cacti, wildflowers, and palm groves. Animal lovers will also enjoy the wildlife scene in the park -- everything from chuckwallas and iguanas to roadrunners and red diamond rattlesnakes have been spotted here.
The park has been designated a National Natural Landmark by the National Park Service.
Flora and fauna
There are miles and miles and scenic and historic trails... You couldn't see it all in a day if you tried!
A park map: replete with hiking trails, campgrounds, dirt roads, paved roads, points of interest, etc. Roughly $2.00 at the Visitor Center: 200 Palm Canyon Drive, Borrego Springs, CA. 92004-5005
Make sure you drink lots of water. High winds and a hot sun can prove dangerous.
There are small motels located in Borrego, smack dab in the middle of the massive state park.
Camp sites are available for $25 per night in most locations or you can camp for free in the primitive camping areas and really get in touch with nature! However, make sure you bring your own fire-ring (or something like it- a metal garbage can lid works great) as it's illegal to make fire upon the ground. It causes great damage to the eco-system. Pack EVERYTHING (including ashes from the fire) out with you. Leave the place like you found it, or do a good deed and scout out old trash left by others that can be dangerous to the natural habitat.
There's plenty of room to get lost so make sure you have a map, water, and tell people ahead of time so they know to worry if you don't show up when you're supposed to.
Watch out for rattle snakes and scorpions... but most of all, the sun. Drink lots of water.