A Spanish artist builds his own castle.

Following the trail of an old metro line, this scenic path is haunted by a creepy spriggan statue.

A relic of Victorian grandeur hides beneath a busy South London road.

The remains of Crystal Palace Great Exhibition of 1851.

A 2000-year-old Roman amphitheater lies just below Guildhall Yard.

This wildly-tiled artist's palace is a living and growing account of the creator's life, loves, and labors.

2300-year-old Roman road connecting the empire.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

The Thai Army has dug deep trenches along the Thai/Myanmar border to prevent drug smuggling.

A Buddhist shrine in a cave protected by macaques next to dark passages lined with creepy paintings.

An enchanting work of outsider art, full of whimsical sculptures and carvings.

Despite its grandiose name, this enigmatic first-century void under the town is no cave, and it's possibly not a palace either.

The walls and streets of the ancient city are peppered with penises.

A little-known park with unusual, half-ruined structures and a mystical energy.

A two thousand year old brothel uncovered in Northern Greece.

An abandoned bell tower in the middle of nowhere is the last testimony of a forgotten medieval village.

This pink watchtower served as the seat of the Greek government after independence from the Turks.

This massive fiberglass Gulliver turns every visitor into a Lilliputian.

The "Little Ones," show Portugal in full miniature splendor.

One of the largest and oldest caravansaries in Persia.

A historic trade hub teeming with gorgeous architecture, colorful goods, and vibrant designs.

The oldest monument in Marrakesh and the city's only surviving example of Almoravid architecture.

Mine shafts and hard pastries await visitors at this massive mountain of salt.

Walls of stone rise up from sinkholes caused by underwater erosion.