A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

A lush oasis full of vibrant plants and striking geometric displays.

This glass skywalk offers vertiginous views down the volcanic cliffs to the beach below.

Local legend holds that if you can make it up this steep cobblestone stairway without taking a breath, you'll have wish come true.

This platform is now a memorial dedicated to those who were deported during the Holocaust.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

Created as a "model concentration camp" to hide Nazi atrocities from the international community, this former camp-ghetto now holds a museum and memorial honoring the lives lost within.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

This walkway is so narrow it needs its own light to stop pedestrian traffic jams.

This automated sculpture of two men peeing will spell out text messages with their micturition.

Macabre astrological automaton clock dating to the late 1400s.

The first museum in the world devoted to sexual gadgetry.

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

The slender brass strip in Prague's Old Town Square was used to tell time from 1652 to 1918.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

A highly-criticized monument in Budapest has become the site of a makeshift Holocaust memorial.

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

Uh, pardon me, ma'am, but I couldn't help noticing that there's a Columbo statue in the middle of Budapest.

This landmark Victorian folly rewards visitors with spectacular views over the Peak District.

This crumbling folly looks like an enchanted left over from Middle Earth.