Hamburgers are intensely proud of their tunnel beneath the river.

Once the tallest building in the world, this abandoned church is now a monument to the destruction of WWII.

Model Trains and Much More in Hamburg.

This futuristic German television spire is actually the world's largest digital clock.

Twisted buildings adorn the banks of the Rhine river.

This fairy tale forest hides scenes from some of the more obscure and bizarre Western nursery stories.

Go inside a revolutionary, cage-less zoo where 35 species live and some of them roam free alongside their human visitors.

Rare wooden escalators lead deep down into an otherwise staggeringly monotonous tiled tunnel.

This enormous steel tube is the biggest speaking horn in the world.

A fantastical 13th-century fortification sandwiched by a modern hotel in central Brussels.

Brussels' favorite peeing boy has a sister.

The struggle of a small Dutch island against the sea.

This small town in the Netherlands has no roads but instead, miles of canals and over 100 bridges.

It appears as if a man is standing behind this giant airport clock, painting the hands in real time.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

The key to turning shifting dunes into the green oasis of Golden Gate Park.

Beneath the southern end of the Golden Gate Bridge is the “Gibraltar of the West Coast,” a fort built to protect the San Francisco Bay from naval attack.

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

A collection of 20th-century automata, penny arcade games, and musical contraptions.

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

The century-old bell and clock tower at UC Berkeley is the third-tallest in the world, and has fossils.

An alley covered with 20 years of bubble gum.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.