S1 E2 ∙ Sweden ∙

Exploring Sweden's passion for subterranean spaces, and how the nation has taken extraordinary precautions to protect itself - by excavating an astounding 65,000 nuclear bunkers.

Series Selector for Underground Worlds

All episodes for series 1 of Underground Worlds

S1 E1 · Gibraltar

Incredible feats of human endeavour, revealing what people have built, where, how and why.

S1 E3 · Switzerland

A look at some of Switzerland's 300,000 subterranean bunkers built across history.