This staircase full of Mayan hieroglyphics is perhaps the largest single text in the world.

This macabre masterpiece of a mural is one of Francisco Goya's "Black Paintings."

The oldest giants in Catalonia are now displayed in a 14th-century Gothic church.

Possibly the oldest church in Barcelona, this basilica has its pagan and Christian mythologies all mixed up.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

These magnificent city walls rise from the barren sun-baked Spanish plains like something straight out of a fairytale.

The Old Courthouse takes visitors on a captivating trip through St. Louis' timeline.

Speak to a companion on the other side of the room loud and clear through this architectural anomaly.

This Florida sinkhole hides a rainforest-like micro-environment in its depths.

Four metal statues of massive animal penises stand outside the university's Animal Sciences building.

San Francisco's oldest operating hotel, with a Victorian atmosphere and a "haunted" fourth floor.

The oldest house in the capital of Silicon Valley.

This restaurant's marvelous musical machines include a self-playing violin.

A giant chess set, minus the psychedelic drug trip.

For roadside fast food, pull over at the giant orange.

It is locally loved and ridiculed for literally looking like poop.

The largest permanent Monopoly board makes one of the longest games even bigger.

The headquarters of a secretive order is also a beautifully-designed park.

A life-sized mammoth sculpture marks the spot where the remains of a Columbian mammoth were discovered in 2005.

An extensive collection of ancient Egyptian artifacts and mummies.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

Its buzzing collection honors vibrator history.

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

These delicate buggers are some of the rarest fossils that have bubbled up from the Tar Pits.