A museum dedicated to the history of psychiatric treatment featuring a gallery of art made by patients.

Under a church hides a forgotten 13th-century ossuary containing the remains of around 2,500 people.

An abandoned Roman salami factory has found new life as an art space home to 200 squatters.

Local lore says the devil built this beautiful medieval bridge to help a fleeing bandit.

Great Britain's only hat-making museum.

The largest radio telescope in the world searches for extraterrestrial life from the remote limestone peaks of southern China.

A mysterious ancient network of thousands of perfectly straight lines stretching across miles of Bolivian desert.

An enormous playhouse designed to look like 21 stacked Lego bricks, with another 25 million colorful Legos inside.

A 1,500-year-old, 3-story subterranean city where ancient Persians took refuge in times of war.

Grotesque statues of figures from Buddhist hell haunt the temple's Sin Park.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

A hidden tunnel leads to an abandoned slate quarry that's now a secret swimming spot guarded by cliffs.

Explore 400,000 years of humans' "battle against darkness" in this offbeat but thorough lamp museum.

An exact replica of a colossal Olmec head sits atop a pyramid within a Madrid traffic circle.

Ordinary art transforms to extraordinary thanks to locals' quirky sense of humor.

A lakeside garden in the Southern Alps full of whimsical artwork and thousands of beautiful flowers.

The vertical-axis windmills of ancient Persia have been grinding flour for 1,000 years and counting.

An important pilgrimage site for pagans and early Christians, named for a Celtic goddess-turned-saint.

Romans built the world's tallest artificial waterfall in 271 BC.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

A colorful narrow alley in Cuba is full of street art and sculptures made of found objects.

An ever-growing literary collection housed in the apartment where the Russian author penned his final novel.

This former charity hospital for elderly clergy houses some of Seville’s most treasured paintings.

Step inside the first house designed by Catalan architect Antoni Gaudí, considered to be one of the first Art Nouveau buildings.