This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

This chapel is the site of a yearly pilgrimage that originated during the Middle Ages.

An icon of the city, this chapel features an amazing dome ceiling and offers panoramic views.

A cluster of granite granaries perched on stilts.

A stunning 18th-century site where pilgrims ascend by a series of punishing stairs only to return via funicular.

France's highest manned weather station is the only one still inhabited by meteorologists.

The world's tallest bridge is also possibly the most elegant.

A stunning cemetery famous for its extraordinarily delicate & lifelike mourning sculptures.

These quaint French houses dangle precariously over a precipice.

Walk through living pictures and music in the Cathedral of Images.

Sleep in a climate-controlled plastic bubble for the night.

A formerly opulent Italian village is now a crumbling ghost town that no one really knows what to do with.

Five candy-colored villages on the Italian Riviera.

Massive galleon from a box-office bomb docked in Genoa.

The bomb-ravaged remains of of a colossal Neptune.

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

The remains of 40,000 humans, meticulously stacked in a tiny churchyard shed.

Now an entertainment complex, the Lingotto building was once an avant-garde auto factory with a test track on the roof.

Catacombs turned marketplace.

A boutique perfumery fashioned to look like a Victorian-era shop.

Spitalfields' regal market goat is said to be a monument to the area's migrant population but most are pretty sure it's just a goat.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

London's smallest police station is barely the size of a phone booth.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.