Underground Marvels

British documentary series exploring incredible feats of human endeavour underground, revealing what people have built, where they have built it, how and why.

Genre: Documentary

Cast:Chris Jarman , Jason Desporte

1Season 1

S1.E1 ∙ Gibraltar

Wed, Sep 25, 2019

This edition explores the hidden network of tunnels and caves beneath Gibraltar that were instrumental to the Allies success during WWII. Plus, the ultimate super-sewer beneath London and a breathtaking cave system in Postojna, Slovenia.

2Season 1

S1.E2 ∙ Sweden

Wed, Oct 2, 2019

Explores how Sweden has gone to extraordinary lengths to protect itself - by excavating 65,000 nuclear bunkers. Plus, Somerset's Cheddar Gorge and an underground first in Romania.

3Season 1

S1.E3 ∙ Switzerland

Wed, Oct 9, 2019

A look at some of Switzerland's 300,000 subterranean bunkers, the creation of a local entrepreneur shrouded in mystery in England and a network of tunnels deep beneath Slovenia.

4Season 1

S1.E4 ∙ Kingdom of Salt

Wed, Oct 16, 2019

The Wieliczka Salt mine in Poland, some 327 meters deep, where the voids left behind from excavating salt have been transformed into extraordinary spaces, carved by hand.

5Season 1

S1.E5 ∙ Bouzincourt

Wed, Oct 23, 2019

A labyrinth of tunnels underneath a tiny French village which contains mysteries from several historical eras, and a Welsh slate mine that has been given a new lease of life.

6Season 1

S1.E6 ∙ City of Naours

Wed, Oct 30, 2019

An underground city beneath a forest in Northern France built to house 3,000 people, an ice cave under Iceland's biggest glacier, and a subterranean power station in London.

7Season 1

S1.E7 ∙ Jersey War Tunnels

Wed, Nov 6, 2019

The underground bases built by the German army during the occupation of Jersey, and a group of more than 20 underground cities in Turkey, one of which dates back to 800BC.

8Season 1

S1.E8 ∙ The Maginot Line

Wed, Nov 13, 2019

The secrets of the largest subterranean fortress along France's border with Germany, and a look at how a unique precious mineral was discovered in Derbyshire.

9Season 1

S1.E9 ∙ Edinburgh Vaults

Wed, Nov 20, 2019

The sinister history of Edinburgh's vaults and the development of Helsinki's subterranean spaces. Plus, the impact of the building of Naples on the volcanic ground below.

10Season 1

S1.E10 ∙ Dover War Rooms

Wed, Nov 27, 2019

This edition explores the military headquarters built beneath Dover Castle during the Second World War, and Odessa's catacombs, possibly the largest tunnel network in the world.

1Season 2

S2.E1 ∙ Hotel Bunker of the Apocalypse

Mon, Jan 31, 2022

Exploring the secret, Cold War US government bunker hidden under Greenbrier Hotel, West Virginia. Plus, delving into the depths of a former slate mine in Wales.

2Season 2

S2.E2 ∙ Mystery of the Kentucky Cave

Mon, Feb 7, 2022

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.

3Season 2

S2.E3 ∙ Cincinnati's Secret Caverns

Thu, Aug 19, 2021

Mysterious caverns in the city of Cincinnati are examined. A network of cellars, wells and tunnels in Cincinnati that were used to create the world's most popular beer. Plus, a state-of-the-art Cold War fortress on the shores of Denmark.

4Season 2

S2.E4 ∙ Buried Lab of the Black Hills

Mon, Feb 28, 2022

Buried nearly a mile beneath the Black Hills of South Dakota is a cutting-edge laboratory at the forefront of astonishing scientific research; experts reveal advancements engineers achieved more than a century ago that keep it operating today.

5Season 2

S2.E5 ∙ Ireland's Underground Alcatraz

Mon, Feb 14, 2022

Exploring hidden defences that have kept Cork Harbour, in Ireland, safe for over 400 years. How did this powerful stronghold became a brutal and terrifying prison. Plus, a former submarine base in the fjords of northern Norway.

6Season 2

S2.E6 ∙ Subterranean Silo Survival

Mon, Mar 7, 2022

A decommissioned missile launch facility in Kansas remained one of the best kept subterranean military secrets of the Cold War, and now, experts reveal how this abandoned underground complex transformed into a state-of-the-art survival bunker.

7Season 2

S2.E7 ∙ Italy's Subterranean Secret

Mon, Mar 14, 2022

Exploring caves beneath Orvieto in Italy, originally built by the Etruscans long before the Roman Empire.

8Season 2

S2.E8 ∙ Grand Canyon's Lost Treasure

Thu, Sep 23, 2021

Exploring inside the Grand Canyon Caverns - North America's largest dry cave system. Plus, Cold War radar bunkers around the UK.

9Season 2

S2.E9 ∙ Murder Raid Tunnels

Thu, Sep 30, 2021

Exploring the extensive air raid tunnels hidden beneath Ramsgate.

10Season 2

S2.E10 ∙ Medieval Maze of Secrets

Thu, Oct 7, 2021

Exploring the maze of of 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.