Under the streets of La Rochelle, a former wartime bunker holds some surprising secrets.

Atop this iconic central Brighton monument sits an inaccurate but innovative time keeping device

An ancient Roman theatre restored to its former glory in the Spanish city of Cartegena.

A long enclosed walkway provides a daily free light show with hypnotic effects.

Before construction of the famous Tintagel Castle, this site in Cornwall was likely a prosperous Dark Age trading port.

A storied British pub where customers leave messages in the walls.

A small cave network was discovered under a home in Xagħra, in 1924 when the owner was digging a well.

In 1888, a resident of Xagħra, Malta, discovered a small underground chamber filled with stalactites and stalagmites when digging a well.

A former smuggler's haven houses "The Chapel" and its mysterious carvings.

This 19th-century aqueduct provides insights into how water was supplied to Victoria on the island of Gozo before modern plumbing.

Picturesque basketball courts sheltered by historical defensive walls and with an enviable sea view.

This blue plaque commemorates the unexpected origin of one of the world's most beloved deserts.

This ruined castle is said to be the legendary keep of a Viking princess.

A granite plane marks the site where a French aviator completed the first airplane flight across the English channel.

An ancient knight and a symbol of the city's freedom.

Gargoyle head that brings good luck.

This memorial to local World War II heroes is slowly being reclaimed by nature.

Tucked between a side street and a theater, this arch once led to a prestigious riding school, and now opens to a courtyard and community garden.

This concept building is the UK's first attempt at making a permanent structure of nothing but trash.

One fisherman has used his love of pebbles and shore to create a crazy garden of rocky art.

Though it was originally dedicated to the Hindu god Shiva, Baphuon was converted to a Buddhist temple in the 15th century, complete with a massive hidden statue.

This desolate boat was once a key form of public transportation for Portslade residents.

A 16th-century artillery fort built to protect England against European invasion.

This tiny alleyway is now a shrine to a subculture riot between the mods and rockers.