It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

An ancient Viking runestone hidden in plain view in Stockholm's old town.

A tower marking the spot where Yugoslavia began its resistance against the invading Nazis stands neglected, but not quite forgotten.

This Luxembourg cave is covered in cryptic looking marks left by mining activity.

Unchanged for centuries, this medieval library keeps its books in chains.

The struggle of a small Dutch island against the sea.

Croatia's towering concrete blossom grows from the site of a World War II concentration camp.

A grand Yugoslav memorial to the group of partisans who fought and died resisting western Serbia’s Nazi occupation.

Someone left a Boeing 737 in a field in southern Bali.

A haunting theme park is slowly being swallowed by the jungle.

This former steel and coal plant is now a neon-lit industrial fantasia.

This massive steel pyramid can be entered by a set of jagged steps that let visitors stand in its heart.

No need to strap in for a "ride" on this walkable roller coaster.

A grassy pyramid named after a French battle.

Iceland's largest geothermal mud pool is a little bit haunted and a little bit dangerous.

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

Three columns of volcanic rock shoot out of the ocean.

This wrecked airplane has been sitting on a black sand beach since the 1970s.

This beautiful, historic church looks like something out of a simpler past.

This fantastical waterfall is hidden in a cave located in a cracked cliff.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.