2012 visitors: 352,517 Known for—you guessed it—its towering Redwood trees (some of which approach 400 feet tall!), this northern California gem is also home to open prairies, oak forests, wild rivers and 40 miles of rugged, unsoiled Pacific coastline. Despite being on the California coast, this park is even more isolated than the relatively empty Lost Coast. That makes it perfect for exploring the peaceful trails that wind through hushed Redwood groves, ogling herds of Roosevelt elk and checking out the open-air aquariums of the coastal tide pools. For more information.