The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

The final resting place of the poets Shelley and Keats.

2300-year-old Roman road connecting the empire.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

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

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

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

Architectureal fantasy quarter of Rome.

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

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

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

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

A clear blue swimming hole with hidden caves, still unexplored.

A tree bears footwear on the loneliest road in America.

Brain collection and database that narrows the gap between man and animal.

The first fresco Diego Rivera painted in the United States can be found in the former San Francisco Stock Exchange.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

San Francisco's newly reopened hands-on science museum.

Nestled between a college and a golf course, the garden is home to more than 2,500 rhododendrons.

No two pieces are exactly the same at Portland's hippo-themed hardware store.

This sandstone mansion was the home of two of Oregon's most important pioneers.

10,000 flowered plants bloom in the City of Roses.

Portlandia is the second-largest copper repoussé statue in the United States.

The magic's in the hole!