This encrypted monolith protected a secret of Norse mythology by hiding in a church wall for over a millennium.

For a couple of months each year this Swedish city turns into a festive neon phantasmagoria.

Enigmatic bug-like sculptures mystify drivers along a Swedish highway.

The dome-shaped reservoir of this old water tower produces unique acoustic effects.

Micro-nation based around a nine-story high illegally built tower.

A memorial to a Swedish hockey player's "encounter" with aliens.

Home to three historic ships from the age of Vikings.

Housing the famous Norwegian ice-defying 19th century polar exploration ship.

The Brutalist building harbors an unusual inverted dome that swoops down over its central sacred room.

Oslo's historic toboggan run has been letting thrill seekers slide from train stop to train stop for over a century.

According to legend, this boat-shaped henge is built over the grave of a mythic king.

Giant origami sculptures tucked into desert scenery beckon passers-by to explore further.

A unique geological area spiked with wind-carved rocks that resemble teepees.

This pseudo-steampunk weapons facility is the world's largest wood and glue structure, and packs quite a wallop.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

The only thing stranger than stumbling onto these philosophical musings is the story of the homesteader who created them.

Sunset-colored dunes of volcanic ash make taking a poor photo impossible.

This strange geological landscape erupts with sudden bursts of water.

A Maori village obliterated by an 1886 volcanic eruption.

Eons old volcanic activity created one of the most stunning rock formations in the United States.

A hard-to-reach oasis in a desolate corner of Death Valley National Park.

A European-style bath house in Chicago.

This morbid, delightful curiosity shop offers everything from animal bones to human teeth.

A sacred lake composed of over 300 separate pools of highly concentrated minerals.