son doong cave

Photo: Ryan Deboodt,

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The Inspiration: "Leave the door open for the unknown, the door into the dark. That's where the most important things come from, where you yourself came from, and where you will go." — Rebecca Solnit

The Place: Son Doong Cave; Phong Nha-Kè Bàng National Park, Vietnam

The Reason to Go: Possibly the largest cave in the world, Son Doong can fit a flying Boeing 747 in its largest section and is home to a jungle filled with 100-foot-tall trees, massive 260-foot stalactites and even its own climate. But the trek to get there isn't for someone who circles a parking lot to find a spot close to the storefront. Son Doong Cave is part of a network of recently discovered monumental caverns in Phong Nha-Ke Bang National Park, and it requires (among other things) roping across a river, climbing massive slick boulders and scaling up a 200-foot wall to reach it.