The California Channel Islands lie off the California coast between Point Conception and the Mexican border. Public visitation is allowed on six of the eight islands. These include the islands of Channel Islands National Park, located primarily near Santa Barbara and Ventura. Much of Santa Catalina Island, near Long Beach, is also open to public visitation. All six islands that are open to the public offer campgrounds, miles of hiking trails, kayaking, swimming, snorkeling, diving, whale watching, plus spectacular views. Catalina offers all of these, plus entertainment that also available in a modern tourist destination.

Most people begin their discovery of the islands and the surrounding ocean by taking a day trip to the closest islands (Anacapa, Santa Cruz and Catalina) or by whale watching near the islands. A day trip offers spectacular views of the ocean and a very good opportunity to see dolphins, whales and other wildlife. Whale watching trips focus and the marine life, and usually do not include an opportunity to land on an island. Day trips that land on an island offer the opportunity to hike on trails and explore visitor centers (Anacapa and Santa Cruz Island) or to visit the city of Avalon or Twin Harbors on Catalina Island.

Overnight trips offer visitors the opportunity to see more remote parts of the islands that are not accessible to day trippers. The only island that offers amenities like hotels and restaurants is Catalina (which also has campgrounds). Otherwise, you stay in campgrounds, bring your own food, and in some cases, your own water. San Nicolas and San Clemente Islands are owned by the U.S. Navy, and the public is prohibited from landing there, although some charter companies offer diving trips near those islands.