This garden houses the remains of the ancient Greek port of Marseille.

Longest canal tunnel in the world, abandoned in the 1960s.

This modern museum of Mediterranean culture is surrounded by a surreal concrete honeycomb.

This historic island prison holds one of the dungeons from the Count of Monte Cristo even though it is a work of fiction.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

A gorgeous example of 13th-century Gothic architecture.

One of London's oldest houses contains a mixture of both old and modern features.

According to legend, this tomb holds the secrets to time travel.

One man's attempt to stay one step ahead of the church.

A larger-than-life house of cards stands outside the house of a former fashion designer.

Read a book with a glass of wine at this classically restored bar.

An authentic, seaworthy replica of the ship that sailed to Newfoundland in 1497.

A museum dedicated to one of Portugal's most celebrated writers.

Little-known artist couple chose a former silk factory as the location for a museum dedicated to their work and other avant-garde art.

This tile-work piece featuring a chicken riding in carriage is both a remarkable artistic creation and a social commentary of politics and culture in 17th-century Portugal.

This museum tells the history of Day of the Dead sugar sculptures.

If you fly into Edinburgh Airport, it's possible to spot this prehistoric site without even getting off the plane.

An unassuming music museum recounts the rags to riches story of a dramatic Portuguese genre.

Invented in the mid-19th century, this machine could send copied images via telegraph lines.

The ruins of a church destroyed by both the Great Fire of London and the Blitz, now turned into a peaceful garden.

This underpass became an unlikely piece of cinematic history after its appearance in 'A Clockwork Orange.'

Tucked away behind the mansions of Mayfair, this picturesque garden is a hidden London treasure with a spooky past.

What might be the oldest living tree in London has survived fires, bombings, and estate agents.

On the wall of this medieval walkway, a symbol of the Spanish Inquisition.