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

A striking public sculpture representing the period of martial law in Communist Poland.

Museum dedicated to "the man who moved the Earth."

The silly symbol for an underground protest group is now scattered around the city.

What was once an underground Nazi city is now Europe's largest bat reserve.

Limestone caves with spectacular showcase chambers.

This church, buried halfway in lava rock, is all that remains of a Mexican village destroyed by a volcano.

The "world's smallest volcano" has been used to store meals and dispose of dead bodies.

This former quarry is now a picturesque gorge that hides a sunken lake.

The largest stone moai on Rapa Nui.

A renegade art installation in a small Vancouver park is now officially sanctioned by the City Parks Department.

Traditional 15th century Chinese garden in the middle of Vancouver.

Surprisingly Delicious Asian-Style Hot Dogs.

A working steam clock, one of only a few in the world, located in Vancouver's Victorian Gastown.

A pixel art killer whale is frozen mid-leap in this Vancouver square.

The 3.8 billion-year-old rock proves that tectonic plates may have been shifting longer than we thought.

These ominous lava formations were said to be an entrance to the netherworld so of course they inspired a famous metal band.

A formerly glacier-tipped volcano that inspired none other than Jules Verne.

The largest whale museum in Europe allows visitors to walk among life-size giants.

Rising from the sea like a stone monster.

The world's longest known cave system.

The history of funerals and funerary customs.

First known as the "Sample House," this construction mash-up was meant to be a living catalogue of building styles.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.