The remains of this 2nd-century Roman temple are incorporated into a modern building.

An ancient Roman temple first dedicated to an emperor's wife is now a church.

A massive marble foot is tucked away in a small alley near the Pantheon.

This is the oldest Roman-made bridge in the city still existing in its original state.

One of Catholicism's four major basilicas has a series of papal portraits that are said to predict the end of the world.

This delightful little museum is dedicated to only one thing: pasta.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

Architectural monsters are devouring this palace's every door and window.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

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

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

Go inside to really appreciate this 500-year-old technological masterpiece.

According to tradition this is the oldest church in Venice, but its actual age is a mystery.

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

This New Orleans tree is filled with hidden chimes that produce a carefully tuned melody.

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

These ruins of a pre-Columbian cliff village are among the most beautiful and well preserved in New Mexico.

French prisoners carved these boats from the bones of their meat rations.

A series of modernist treehouse hotel rooms grace the outskirts of an Arctic forest.

An oddities shop that dabbles in the deathly and beautiful.

Walking around West Harlem reveals a scavenger hunt of beautiful bird murals.

A mapping error in the 19th century made loggers think this section of the forest was underwater.

A Viking-style brewpub named for a Norse sea giant, in the heart of fjord country.

A golden egg-shaped sauna in the Arctic tundra.