Jan 10, 2022 · 45m
Exploring the extensive air raid tunnels hidden beneath Ramsgate. Also, how the former thriving mining town of Butte, Montana repurposed the 10,000 miles of tunnels.


British documentary series exploring incredible feats of human endeavour underground, revealing what people have built, where they have built it, how and why.
Browse every episode and jump into details.
Jan 10, 2022 · 45m
Exploring the extensive air raid tunnels hidden beneath Ramsgate. Also, how the former thriving mining town of Butte, Montana repurposed the 10,000 miles of tunnels.
Jan 17, 2022 · 45m
Exploring inside the Grand Canyon Caverns - North America's largest dry cave system. Plus, Cold War radar bunkers around the UK.
Jan 24, 2022 · 45m
Exploring the forgotten underworld hiding beneath the streets of Cincinati, USA. Plus, a state-of-the-art Cold War fortress on the shores of Denmark.
Jan 31, 2022 · 45m
Exploring the secret, Cold War US government bunker hidden under Greenbrier Hotel, West Virginia; Plus, delve into the depths of a former slate mine in Wales, UK.
Feb 7, 2022 · 45m
Exploring the vast 400-mile Mammoth Cave in Kentucky, USA. Plus, a newly constructed opening into a metal mine in Wales - untouched for over 70 years.
Feb 14, 2022 · 45m
Exploring hidden defences that have kept Cork Harbour, in Ireland, safe for over 400 years. Plus, a former submarine base in the fjords of northern Norway.
Feb 21, 2022 · 45m
Exploring long narrow tunnels beneath Exeter that were built in medieval times to protect the city. Plus, a marble quarry under the pine forests of Vermont.
Feb 28, 2022 · 45m
Exploring a former gold mine turned scientific laboratory in South Dakota. Plus, limestone tunnels in London and a former water cistern in Denmark.
Mar 7, 2022 · 45m
Exploring old tunnels in an abandoned tin mine beneath the moors of Cornwall. Plus, former Atlas missile siloes in Kansas and tunnels hiding under Valetta.
Mar 14, 2022 · 45m
Exploring caves beneath Orvieto in Italy, originally built by the Etruscans long before the Roman Empire. Plus, a former limestone mine under Kansas City.
Quick answers about this season's release timeline and episode lineup.
Underground Worlds Season 2 premiered on January 10, 2022.
Underground Worlds Season 2 has 10 episodes.
The season opens with Season 2 Episode 1, "Murder Raid Tunnels". It aired on January 10, 2022.
Go to Season 2 Episode 1