At the crypt of St. Mary of Eulogies and the Dead you are left alone to ponder mortality among piles of skulls.

The yawning maw of this pagan visage is said to bite off the hands of liars.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

The former home of a trailblazing surrealist is still filled with haunting dolls and grim paintings.

Most prolific publishing house in the 1600s open to the public.

This whimsical statue dumps water on its head to symbolize knowledge flowing into his brain. Or maybe booze.

The bronzed skull of a beheaded traitor was affixed to the city gate in the 17th century.

Somewhere there is a giant who can no longer poop, but now travelers can stay inside his anus.

Artwork tucked within the trees greets visitors with surreal sonic experiences.

This Greek temple, open only an hour a day, was the site of a war of tastes between an architect and an artist.

A marble Lucifer hides behind the pulpit of this Gothic cathedral.

Hiding the longest subterranean river known in the world.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

Part modern art project, part traditional chapel, this see-through church is only substantial from the right angle.

This modern arts center is built around a gem of late-Baroque architecture.