Boyden Cavern is located in Kings Canyon, Giant Sequoia National Monument, and lies beneath the massive 2,000 foot high marble walls of the famous Kings Gates. The cavern opens for the summer season usually in late April and is open 7 days a week, at limited capacity, until the end of October/ early Novemver (depending on weather.) Reservations are recommended. In addition to the online tickets, walk-up tickets may be available if guides are available. Visit the gift shop for a selection of souvenirs, snack items, drinks, etc. To book in advance: https://boydencavern.com. Visitors are delighted to find that the magnificent Giant Sequoias are complimented by the natural beauty of the underground cavern. This tour is suitable for all age groups, from kids to senior citizens. There is a steep, though short, five-minute walk to the cave entrance. Although Boyden is located in the Sequoia National Forest, visitors must pass through Kings Canyon National Park to access the cave. The Park entrance is located near Grant Grove on Hwy 180.The Walking Tour lasts 45 to 60 minutes round trip. Departure times vary based on availability during the season.