Conquering an Infinite Cave

There’s a jungle inside Vietnam’s mammoth cavern. A skyscraper could fit too. And the end is out of sight.

“Past the hand of dog, watch out for dinosaurs,” says a voice in the dark.

I recognize Jonathan Sims’s clipped, British military accent but have no idea what he’s talking about. My headlamp finds him, gray muttonchops curling out from beneath his battered helmet, sitting alone in the blackness along the wall of the cave.

“Carry on mate,” growls Sims. “Just resting a buggered ankle.”

Premium Paywall - Domestic

Read This Next

Rivers and lakes are the most degraded ecosystems in the world. Can we save them?

The world’s oldest known wild bird just turned 70—why she’s so special

Buried for 4,000 years, this ancient culture could expand the 'Cradle of Civilization'

Go Further

Subscriber Exclusive Content

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet