The oldest residential street in Europe also features an optical illusion.

An isolated 17th-century chapel on a remarkable site once dedicated to Celtic sun worship.

Constructed during the 7th century this is one of the oldest largely intact Christian churches in England.

The medieval legend behind this holy well was one of the inspirations behind "Alice's Adventures in Wonderland."

Inside this former medieval prison is a collection of objects designed to inflict unbelievable pain and suffering on the human body and mind.

These paved rills bring freshwater into Altstadt and could spell wedding bells for whoever stumbles into the waters.

Europe's official "zero-level," the equator of elevation.

Double spiral staircases are not unheard of, but they are very rare.

A neighborhood park in the city of Cáceres hides what some believe are revolutionary examples of Neanderthal cave art.

This proud Teutonic warrior rises out of a German forest heralding a victory and measuring lightning.

340-foot statue built to honour the Heroes of the Soviet Union.

The world's tallest statue of a woman wields the world's tallest sword and is at risk of toppling over.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

This floating garden in the sky is straight out of a fairy tale, but the real thing is nothing short of magical.

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

This ancient Roman arch misled treasure hunters for centuries.

A striking glass tribute to two sisters who suffered during Scotland's "Killing Time."

A hidden plaque is the only reminder of the lost palace where two storied English kings were born.

This structure atop a craggy cliff in one of the most beautiful parks in Paris boasts an unbeatable view.

These ruins of a medieval church are full of architectural mysteries.

Remnants of a 4th-century church with vivid medieval frescoes and ancient sarcophagi hide beneath this old basilica.

These legendary stone steps were once used to haul coffins up the rockface.

The commemorative stone column conceals a secret laboratory.

This single-track road rewards brave drivers with stunning Scottish scenery.