- National Park,
The Algodones Dunes northeast of El Centro, California are variously known as Glamis Dunes (after a tiny town nearby) or as the Imperial Sand Dunes Recreation Area. Whatever you call it, the area is famous for the 45 mile long sand dune at the base of the Chocolate Mountains. About 40% of the dunes, mostly below California State Route 48, are open for offroad, ATV, or motorcycle use. The area is very popular with the weekend warriors from San Diego, and can be very populated during weekdays - more than a quarter million people during some major holidays. The area is also a popular movie and TV locations, whenever a sandy desert is required.
The dunes have had a long history with offroad recreation. The first dune buggy was developed here. As the largest dune environment in the United States, there is much to see - either by ATV to the south, or by short excursion by foot to the north.
If you are interested in exploring the Glamis Dunes, be sure to check what areas are open to offroad use. And be sure to bring lots of water. The temperatures during the summer will easily top 100 degrees, but it cools off nicely during summer nights and winter days (about 70 degrees) to allow for camping, ATV or motorcycle touring, and more.