A historic observatory now an astronomy museum beautifully situated at the moat of the Middle Age city centre.

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

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

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

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

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

A floating cat sanctuary on an Amsterdam canal.

Amsterdam's Red Light District leaves little to the imagination.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

The attic of a four-century-old canal house hides a clandestine church.

The largest collection of handbags in the world, the oldest of which were used to carry Bibles, primarily by men.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

A Nesting Doll of Churches.

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

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

The 1936 Summer Olympics site is a crumbling remnant of sportsmanship and a history its host country would like to forget.

A 14th century bridge built as a fortress, where the devil lurks on one of its towers.

This life-size replica of the Statue of Liberty's flame is also a tribute to Princess Diana by default.

The ruins of this antebellum sugar plantation are the end result of a Seminole attack during the Florida Wars of 1836.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

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

Ever wanted the laymen's version of your credit card fine print?

Berlin's old airport.

The most visited, and possibly most controversial, museum in Germany.