A psychedelic labyrinth on the San Francisco bay.

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

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

The ruins of an 11th-century Norman castle with a rare, perfectly circular shape.

The twists and turns of this serpentine maze are over 170 years old.

A island reachable by a causeway at low tide is possibly one of the earliest Western European locations to be identified in text.

A neolithic dolmen that was rebuilt after collapsing during the 19th century.

These picturesque ruins crumble beautifully into the ocean.

A legendary rocking stone, returned to its clifftop perch.

A open air theatre built on a cliff by an eccentric British woman.

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

The Bauhaus-style former industrial complex is considered the world's most beautiful coal mine.

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

An industrial relic is now one of Europe's most staggering art spaces.

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

A tiny, intricate model railway system.

Built to test magnetically levitated elevators, the tower also boasts Germany's highest visitor platform.