The stalactites and stalagmites of the glass cave of the Sequoia National Park, an expanding underground extension that has been closed for four years, will be accessible again this summer.
But to enter during the open season from May 23 to September 7, you will need tickets, which are now available.
Guided visits are considered strenuous with the steep terrain.
(Sequoia Parks Conservancy)
Visitors will walk through the cave in 50 -minute guided group tours, inspect mineral formations and listen to the history of the cave and the rare geology. The rangers describe the path, a steep half mile to reach the cave, then a half mile circuit inside, as “strenuous”, with possible meetings with poisonous oak, bees, rattlesnakes and rocks that fall. It is not suitable for young children or any person with claustrophobia, the rangers say, and the stairs are more or less as high as a 20 -story building.
The cave is one of the 275 known caves in Sequoia and the neighboring Kings Canyon National Park. The only publicly accessible cave in the park, has been open to visitors since the 1940s, which makes it one of the most visited underground reference points in California.
Savannah Boiano, executive director of Sequoia Parks Conservancy, said that many trees died near the cave in the drought of the 2010, then turned on in the fire of the KNP 2021 complex, forcing the closing of the cave. Then winter storms arrived in 2023, even more damaging the path of 6 miles to the cave. To prepare for reopening, said Boiano, the teams eliminated the dangerous dead trees, repaired the roads and replaced the electrical system with solar energy of the cave.
“It really has been the epicenter of some natural disasters,” Boiano said.
Crystal Cave includes more than 3 miles of corridors surveyed, carved by water for approximately one million years. Its temperature is constant of 50 degrees. Its walls are marble, not the granite that dominates the Sierra Nevada range, and an underground current runs along with much of the cave path. The last and largest “room” is known as Marble Hall.

Visitors will walk through intricate corridors.
(Sequoia Parks Conservancy)
Sequoia Parks Conservancy manages reserves for Tours ($ 21.20 for adults, $ 11 for children under 10 years; prohibited pets), offered from 9 am to 3 pm in May, tours are offered from Friday to Monday, Tuesday to Thursday. From June to September 7, the tours are daily. Photography is allowed, but flashes, tripods, monopods and selfies are prohibited. If the weather forces a caves closure, reimbursements are offered.
Tickets will not be sold in the cave, said conservation. Park Rangers advise visitors to buy Cave Tour tickets two months before, noting that historically, the tours have been exhausted in July and August.