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.
All episodes for series 2 of Underground Worlds
S2 E2 · Grand Canyon's Lost Treasure
Exploring inside the Grand Canyon Caverns - North America's largest dry cave system.
S2 E3 · Cincinnati's Secret Caverns
Exploring the forgotten underworld hiding beneath the streets of Cincinnati, USA.
S2 E4 · Hotel Bunker of the Apocalypse
Exploring the secret, Cold War US government bunker hidden under Greenbrier Hotel in West Virginia.
S2 E6 · Ireland's Underground Alcatraz
Exploring hidden defences that have kept Cork Harbour, in Ireland, safe for many years.
S2 E7 · Medieval Maze of Secrets
Exploring tunnels beneath Exeter that were built in medieval times to protect the city.
S2 E8 · Buried Lab of the Black Hills
Exploring a former gold mine turned scientific laboratory in South Dakota.
S2 E9 · Subterranean Silo Survival
Exploring old tunnels in an abandoned tin mine beneath the moors of Cornwall.
S2 E10 · Italy's Subterranean Secret
Exploring the caves beneath the beautiful city of Orvieto in Italy.
The Buildings That Fought Hitler
Description: This series looks at just some of the buildings that were designed to fight Hitler.; Category: Military & War; 8 episodes available.
The Architecture the Railways Built
Description: Tim Dunn explores the stunning architecture that lines the railway network.; Category: Engineering; 40 episodes available.
Guy Martin's Lancaster Bomber
Description: The history enthusiast honours Lancaster bomber crews of the Second World War.; Category: Military & War; 1 episode available.
Guy Martin's World War 1 Tank
Description: Guy builds a working replica of a WWI tank and drives it at a Remembrance Day parade.; Category: Factual Entertainment; 1 episode available.
How Britain Worked
Description: Guy Martin recreates technical achievements of the 19th century.; Category: Engineering; 6 episodes available.
Guy Martin's Spitfire
Description: Guy joins the two-year restoration of a Spitfire that was buried in a French beach.; Category: Engineering; 1 episode available.
Forbidden History
Description: Jamie Theakston investigates incredible tales from the annals of history.; Category: History; 11 episodes available.
Hitler's Supercars
Description: The rise of Nazi Germany's speed record cars of the 1930s.; Category: History; 1 episode available.
Mega Metro
Description: An international team works on Australia's biggest ever tunnelling project in Sydney.; Category: Engineering; 8 episodes available.
Churchill's Bid to Abolish Britain
Description: This ambitious, striking film challenges our understanding of the Second World War.; Category: History; 1 episode available.
Smoke & Steel
Description: Examining the Industrial revolution - the age of smoke and steel.; Category: Engineering; 6 episodes available.
Great British Landmark Fixers
Description: Teams across the country are keeping our heritage standing, these are our landmark fixers.; Category: Engineering; 6 episodes available.
