The world's first ice hotel is still one of the most elaborate and beautiful.

A series of modernist treehouse hotel rooms grace the outskirts of an Arctic forest.

A serpentine highway twists and turns over the treacherous Norwegian Sea.

The world's oldest individual clonal tree looks like a wimp despite standing tall for 9,550 years.

Stay overnight in the world's most sleekly designed rabbit hole, free of charge.

An extraordinary mechanical calculator designed by the mathematician and philosopher Gottfried Leibniz.

This Stockholm light tower can be controlled by anyone with a smartphone.

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

The world's first clock to use set theory as a measure of time required the invention of a new light bulb just to maintain its obtuse measurements.

A collection of abandoned typographic signs from Berlin and beyond.

Sweden's first nuclear reactor, R1, can be visited 25 meters underground.

A man has revenged his true love's betrayal through tears and stone genitalia.

A floating underwater hotel, created by a Swedish artist.

A small collection of magic tricks and memorabilia is now an apartment-sized museum.

WWII rocket launchpad in rural Germany and site of operation backfire.

Hamburg's first legal sex work is relegated to a gated street that still does not allow pedestrian women.

The small alleys in Lübeck's Old Town are a result of medieval urban sprawl.

Train tunnel running underneath Quebec City.

Big gun installations, built over a massive cemetery, now abandoned & hidden in trees.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

An artsy hidden staircase leads to breathtaking views of San Francisco.

A free, public museum dedicated to the fascinating science of sight.

A museum befitting the city responsible for supplying the majority of the world's LSD.

A mysterious and terrifying public art goblin seemingly meant to inspire local legend.