Medicinal spa created with the discharge from a geothermal energy plant.

Walk in the footsteps of the gods and straddle two tectonic plates.

This mountain fissure hides a secret path to a secluded mossy grotto within the rock itself.

This scenic Icelandic lava flow is named for a pair of Berserkers who were murdered, according to a famous Saga.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

Cold war icon and onetime "hole" in the iron curtain.

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

Duluth mineral magnates built this charming art deco lodge to be their private clubhouse.

Millions of years of oxidation make a drive down this winding Death Valley road surprisingly colorful.

A remnant from the golden age of aviation still in use today, Pan Am's Clipper service took off from this Art Deco gem.

The remains of a World War II munitions factory still haunt the fields of this Twin Cities suburb.

Restaurant in Northern Wisconsin comes with a unique feature: a grassy roof covered in living goats.

A science teacher's dream.

Vikings and Evangelicals have both had a hand in this replica medieval church.

This pebble beach is so beautiful that taking its rocks is against the law.

These ancient sacred grounds granted amnesty to those who managed to reach them.

The real life town from the Pied Piper of Hamelin has a mechanical puppet show that retells the famous story many times a day.

G.V. Black, the Father of Modern Dentistry, keeps an eternal eye on Chicagoan’s teeth from his perch in Lincoln Park.

A winged-helmed, sword-brandishing tribute to German Americans.

A little-known subterranean street runs under some of the best-known buildings in Chicago's River North.

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

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.