Walk underneath a railway bridge over the river Reuss with just a metal grating under your feet.

A relic from ancient Egypt that is purported to have a curse associated with it

The purported midpoint in London from which all distances are measured has a tragic love story at its core

The largest stretch of the Berlin Wall is right on top of the former SS headquarters

A discreet mark on the ground marking the site of the first chapel of the Glacis, dedicated to the patron saint of the city of Luxembourg and the country

A tragic legacy of the attempt to beautify Skopje and line the pockets of corrupt politicians

Built in the aftermath of a devastating earthquake, this cathedral is one of the finest examples of Sicilian Baroque architecture.

Every half hour, the flow of this unusual spring cycles between a rush of water and barely a trickle.

This French castle is said to have once held the Holy Grail but is now a gorgeous mountaintop ruin.

This futuristic observatory at the top of the Pyrénées offers unrivaled views.

One of London’s rare Tudor-era buildings is a fate-defying gatehouse for a church.

The largest of London's subterranean rivers and once a mad, bad center of London life.

Pop culture has helped to keep this iconic British building from being destroyed.

A remarkable medieval structure born from a 14th-century disaster.

A building claimed to be London’s smallest house has an obscure history.

Italian cave with exceptional acoustics and an unsavory history.

A statue of Charlemagne, created in the 1400s, once overlooked the city, and is now located in a crypt.

Check the time in 145 countries at once with this East German relic.

The ground on which Shakespeare’s initial playhouse once stood.

The oldest floral clock in the world still functions today.

The world’s second-largest flood defense barrier has protected London for decades.

Some of the world’s most popular songs came out of this building.

Charming small streets lined with well preserved wooden houses dating to the 18th and 19th century.

This 12th-century castle majestically overlooks the city and the beautiful Mosel River valley.