A perfectly circular stronghold constructed in the 10th century is now a nucleus of Viking culture housing a museum, village, and reenactment of an epic Viking battle.

Peek through a transparent pyramid and drink in the mountain made of books.

Collection of skeletal systems from the "world's leading supplier of osteological specimens."

Massive still life just off the highway in Kansas.

Large Hadron Collider and the Birthplace of World Wide Web.

The bizarre visions of H.R. Giger, tucked away in a Swiss medieval city.

Handsomely crafted representations of our round planet.

Living trees form the structure of an open-air palace.

A German apartment building hosting as many trees as human occupants.

The birthplace of an eccentric alchemist and possible inspiration for the fictional reanimator of monsters.