An alchemist's "magic door" stands in the middle of a Roman park.

Abandoned substation turned village treasure.

Underneath the city that invented pilsners are a series of historic tunnels that have been storing beer for centuries.

A museum of alchemy and a basement laboratory all housed in an ancient building in a Gothic tower.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

According to the Guanches, the aboriginal people of the Canary Islands, the king of evil lives inside this volcano.

Pompeii's less famous neighbor is still revealing her secrets.

The oldest volcanology research center in the world.

The oldest amusement park in the world has been providing a nice spot to have some fun since the 1500s.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Light still pours into the ruins of this ancient Islamic observatory.

A neutrino detector built into the largest man-made underground cavity in the world.

High on a hill overlooking Los Angeles lives a world famous, high power conical Tesla Coil.

The world's largest neutrino telescope searches for secrets of the universe at the South Pole.

Museum on earth sciences featuring a recreation of a famous curiosity cabinet.

Old Danish castle immortalized in Shakespeare's Hamlet.

An exhibition of preserved locomotives housed in a 1950s depot shows the history of Denmark's railway.

This colorful artistic feature atop a Danish art gallery allows visitors to stroll through a rainbow.