California is a state with natural beauty that stretches the entirety of the state to each of its borders. It is also a state where the beauty above ground in some areas pales with the beauty below ground. Like a sunset on an unknown beach, each of these areas offer solitude, otherworldly beauty, and in some cases, some of the most unique terrain on the planet. Even if you've never explored a cave before, each of these spots will interest and intrigue you, and provide you a great introduction to the world below your feet.
1) Lava Beds National Monument. The number one spot on any "best of" list is usually a point of contention, but not in this case. While Lava Beds National Monument may be located in a remote spot in California, it has over 700 lava tube caves; of which over 20 can be explored by all skill levels of the general public without the need for guides or tours. The park also has a rich cultural and historic background; and features some of the darkest night skies in the state.
2) The Arroyo Tapiado. Like the first entry, the caves of the Arroyo Tapiado have been formed by wind and water over thousands of years. Unlike the first entry, the caves of the Arroyo Tapiado are made of mud. While mud caves exist in other places on the planet, they are not as extensive or as well preserved as the thirty plus caves that can be explored in the middle of the Anza Borrego Desert. Like the caves present at Lava Beds, the caves at the Arroyo Tapiado can be explored by all skill levels of the general public.
3) The Balconies Cave and Bear Gulch Cave. These caves are not made by volcanic forces, nor mud, but are great examples of talus caves, and are suitable for beginner hikers or explorers that have never been into a cave before. The varied passages present in the caves and many rock climbing routes in Pinnacles National Park, however, provide great opportunities for advanced cavers as well.
4) Sequoia and Kings Canyon National Parks. Even though both sections of the National Park have a variety of wondrous things to protect above ground, the land of the park would also have been set aside for protection because of the extensive cave network nestled underground. Experienced cavers can explore these areas; but most members of the general public and beginners gravitate toward the Crystal Cave in Sequoia National Park and Boyden Cavern in Kings Canyon National Park; both of which offer guided tours during the summer months.
5) Black Chasm Caverns National Landmark. Like the Crystal Cave and Boyden Cavern above, this cave is only accessible by a guided tour. However, this cave outside Sacramento provides great examples of many common cave features.
6) The Lava Tube, Mojave National Preserve. While this may be the smallest cave on this list; it is perhaps the cave with the most surreal visual feature. Located in the middle of the Mojave Desert, the interior of this lava tube is perfectly punctuated by a heavenly shaft of light year-round. If you're willing to off-road a little bit, this cave is accessible for all skill levels.
7) Subway Cave. Like the caves at Lava Beds; and the Lava Tube listed in Number Six, the Subway Cave in the Lassen National Forest is a lava tube cave. Unlike some of the lava tubes in those spots, the Subway Cave is large - hence the name. It also features perhaps some of the most ominous sounding cave feature names in out of all of the caves in this list.
8) Cave of Munits. This cave represents yet another type of cave found in California, a chimney cave. Located near Los Angeles, California, this cave and Castle Peak represent a sacred area for the native Chumash people.
9) Mitchell Caverns. These caverns could be the greatest caves on this list found in California. However, since 2009, these caverns have also been closed by the State of California due to budgetary concerns; and as of late 2014, will remain closed for the conceivable future. Rumor has it though, that these caves located in the Mojave Desert are fairly special.
10) Big Horn Mine. This cave is less a cave, and more of an old gold mine. Located near Mount Baden-Powell in Southern California, the cave goes back a fair distance into the mountain, and features the remnants of the mining operation outside.
And as an added bonus - the Worst Caves of California (tie): The Vanalden Caves and the Lawrence Welk Caves. Both of these sites have been treated poorly by vandals and various other third parties, and until they can be restored or better protected, are not worth a visit as there are better options.