It's always summer at the beach inside this former airship hangar.

From toys to kettles to scientific instruments, this German museum celebrates the beauty of 20th century design.

An intricate and amazing house built by architect Karl Junker.

A massive underwater sinkhole made famous by Jacques Cousteau.

The deadliest diving spot in the world is also a stunning geological marvel.

An underground city of ancient quarry tunnels hid thousands of Allied soldiers in WWI.

South Korea's love of the silly photograph is on full display at this goofy collection of trompe l'oeil paintings.

The "Prussian Versailles" that is as glorious today as when it was built.

Solar observatory doubles as a daring display of Expressionist architecture, much to Einstein's chagrin.

Started as a kitchen garden, now the second largest botanical garden in the world.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

Fall down the rabbit hole into a surreal journey of human consciousness "from ass to soul."

Art and a pun, all in one.

Home to 10,000 medical specimens including the remains of Rudolf Virchow's extensive collection of pathological specimens.

A surreal museum of extraordinary industrial objects.

An old department store turned Nazi prison turned artist commune.

Blitzkrieg bop your way through Berlin's Ramones Museum.

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

A collection of abandoned typographic signs from Berlin and beyond.

The Buddhist temples of Yamadera, built into a mountain side, feature a viewing deck with sweeping views.