A focal point of the Cuban government, this city square features one of the most iconic images in the country.

The ruins of this Dutch castle sit atop a labyrinth of once-secret tunnels and passageways, dating back over 900 years.

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

Carvings in Turkey's Marble Road may have directed ancient Romans to a hidden brothel.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

The gutted remains of this Estonian mansion are a monument to a tragic love.

The Guardian of Tallinn.

An empty relic of the Moscow Olympics crumbles away in Estonia's capital.

The last bastion of Roman presence north of the Alps looms over a German town.

Hide from the tourist hordes in these relatively unknown, and unguarded lava caves.

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

World's tallest monolithic statue has served as a pilgrimage site since its completion in 993 CE.

This precariously balanced boulder is said to be a hunk of stolen butter dropped by the gods.

Picnic on the seashore in the footsteps of ancient kings, protected by giant mythical cat beasts.

This indoor ski resort has a mountain contained inside a mall.

In terms of history and architecture, this is one of the most remarkable cemeteries in the world.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

A grand imperial capital left to fall into magnificent ruin.

The history of sea-faring refuse and disaster is on cramped display in this Netherlands folk museum.

Go inside a revolutionary, cage-less zoo where 70 species of monkeys roam free alongside their human visitors.

This unattributed sculpture in Amsterdam is hiding in plain sight.

An out-of-place slice of France, smack in the middle of Shanghai.