This now museum began supplying water to Sunderland during the mid-19th century.

The former "holiday home" for monks at the Durham Cathedral.

Nicknamed the 'Chestergate Hotel,' the underground tunnel had beds, lights, and even flushing toilets.

Inside a Scottish castle hangs the tattered remains of a flag with murky origins and supposed magic powers.

Order a salt beef-loaded beigel at any hour of the day or night at this East End institution.

This forgotten chalk mine was reopened thanks to a massive effort from the local community.

The grand complex of buildings that comprise Liverpool's Exchange Flags includes a vast World War II bunker that has been frozen in time.

Created as a punny statement about genetic engineering this monstrous hybrid statue has become a beloved icon.

This Norman castle was once the site of a Victorian-era prison, and now exists as a luxury hotel.

Though it's not the largest, this one-kilometer outdoor market is reportedly the longest in Europe.

This abandoned gun tower was built to defend the River Thames from a French naval attack.

This gorgeous space is England's largest independent library outside of London.

The world's oldest model village.

Behind one of the world's most impenetrable vaults is a massive collection of retail silver.

A nuclear bunker built to shelter the politicians and important people of Scotland in case of nuclear attack.

A once extravagant mansion, now reduced to ruin.

This disused Cold War bunker has been restored to all of its early 60s glory.

A museum marks and documents the site of the Titanic's launch.

A petite castle folly in the English countryside.

A unique tribute to the millions of animals who served and died for the British military.

These docile dragons are ideal inhabitants for the conservatory greenhouses.

One of the few standing Roman lighthouses and a labyrinth of tunnels are a couple of the secrets at this historic castle.

Its collection includes a broad array of social, geographic, graphic design, and political history.

A beautiful ruin of a 14th-century Plantagenet castle built by a medieval mercenary.