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

One of several skulls claiming to belong to the beheaded St. John the Baptist is on display at this Roman church.

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

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.

An alchemist's "magic door" stands in the middle of a Roman park.

A Nesting Doll of Churches.

Charles Dickens was not a fan of the ghastly wall dressings in this 6th century church.

These stark white cliffs were spat up by the sea and are slowly being retaken by it.

A prehistoric landscape hidden in the cliffs of Maha'ulepu.

A hospital closed seemingly in the middle of operations, leaving behind fodder for horror films and ghost hunters.

This iconic L.A. bookshop is housed in an abandoned bank—both symbolic and chic.

During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.

Version of the French Riviera destroyed by the sea.

Art in the form of a winding, man made crack in stone.

A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.

A classically inspired temple in Redwood City.

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.

Once the gateway to the utopian dream-village of a Civil War embalmer.

An abandoned, unfinished mansion on grounds strewn with lava rocks.

A winding path built in secret on the edge of the continent.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

A huge musical instrument played by the ocean.