Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

A chapel on a volcanic core, marking the end of a successful journey.

Venice's "Island of the Mad."

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

An Aztec snake god has taken the material form of an apartment complex.

A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

This enormous "cloth of the conquest" depicts the Norman invasion of England in mind-blowing detail.

A disquieting Aztec sculpture displays hundreds of stone skulls representing the victims of human sacrifice.

Sitting on an Italian hilltop is this surreal fortress built by the mad inventor of electrohomeopathy.

It turns out that a hurricane-prone beach is probably not the best place to house wild animals.

The middle finger of modernity.

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

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

Brass cobblestones mark the places where individual Holocaust victims were taken from their homes.

This monastery built into a cliff hides a perfectly preserved hermit in a glass coffin.

Temples adorned with intricate, erotic sculptures make up one of the "seven wonders" of India.

An ancient octagonal weather station named for the eight Greek gods of wind.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

Folky pharmaceuticals abound in this medicinal reliquary.

A 200-year-old prison that now houses a peculiar crime museum.

A forest park outside Tallinn full of architectural and artistic curiosities.

These 1,500-year-old remains were found in a mysterious Anglo-Saxon mass grave.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.