The medieval network of canals hidden underneath the city is opened to explorers each year.

The beautiful, ornate weather station is the most popular geocache in Salzburg.

This strange statue features a bust of the famous composer plopped atop a woman's body.

A monument to the thrice mayor of London who according to lore made his fortune by selling his rat-chasing cat.

Black cat statues guard this temple-like Egyptian revival factory.

The geographical center of Budapest is marked with a 10-foot-tall stylized zero.

A baffling beast so absurd a town councilman called it "intellectual vomit in technicolor."

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

Ancient cliffs resembling a kilt on Scotland's second largest island emit an entrancing sound.

This innovative steam machine was no doubt the most famous of the pioneer locomotives.

An unsanctioned shrine that sprung up outside the late singer's home is causing a stir in London's Highgate neighborhood.

Possibly the world's largest hourglass only needs to be reset every New Year's Eve.

Once the home of a hermetic monk, this cave now houses a small church.

Clusters of abandoned buildings hint at the facility's 144-year history with psychiatric health.

A fascinating insight into daily life in the Eastern Bloc.

These stark white cliffs were spat up by the sea and are slowly being retaken by it.

These ancient sunken lanes were naturally tunneled into the soft ground by countless footsteps.

Ancient human remains unearthed around the iconic monument.

There are plenty of wonderful panoramic vistas in Edinburgh, but not many are hidden smack in the middle of the Old Town.

Tiny effigies of the victims of Edinburgh's famous Anatomy Murders.

Remnants of the 16th-century defensive wall still stand unassumingly within Edinburgh.

A plaque marks the underground site of one of London's "lost rivers."

This colorful creation wasn't always a welcome part of Toronto's Moccasin Trail Park.

This hidden art nouveau gem was designed by an architect in search of a national style.