Locals affectionately dubbed this World War I memorial "Tommy."

Derelict chemical plant on the North Sea is a beautiful industrial ruin.

This 1,400-year-old abbey was once a powerhouse for music and intellectualism known across Normandy.

This foolish Victorian sea fort was converted to a deluxe hotel.

This abandoned gun tower was built to defend the River Thames from a French naval attack.

An abandoned tower once used to study the cosmos hides within a thicket of greenery.

This former abandoned hospital, a complex of stunning 19th century buildings, once housed 2,000 psychiatric patients.

Colin Stokes "got a bit carried away" and built a castle that looks like something out of Tolkien.

This shell of a historic manor house on the Isle of Wight is said to be the most haunted site on the island.

The remains of a remote village that once housed over 1,200 dam workers and their families.

The abandoned funicular tunnel was a secret base for the BBC during World War II.

Henry VIII's forgotten castle was built by the gunpowder-obsessed king to be defended solely by cannons.

The intended purpose of this unfinished Elizabethan building remains a mystery.

This medieval manor house was equipped with secret compartments for hiding priests.

This overgrown Victorian chapel made of corrugated metal looks utterly out of place.

These ruins of Francis Bacon's once-magnificent manor are hidden in the English countryside.

This abandoned lock-up was saved because of its connection to a local football team.

The unusual stilted beacon is the town's only active lighthouse.

The sanctuary seems to either float atop the water or sink into the dirt, depending on the water level.

This giant wooden treehouse within a sprawling garden has its own eatery.

Walk through living pictures and music in the Cathedral of Images.

Grottoes, sculptures, and recycled ceramics permeate what was once just a small farm in France.

A village of art and exotic creations.

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.