Video: The Cave Divers Who Explore Sweden’s Longest Underwater Cave

Learn about the cave divers who take part in the Bjurälven Expedition, an annual expedition to explore Sweden’s Dolinsjö Cave.

Currently the longest known underwater cave in Sweden at 1,782 meters (1.1 miles) long, it is located within Bjurälven Nature Reserve in the Jämtland mountains.

[via Micke Tilja]