The last moments of the ill-fated Pompeiians, frozen forever in plaster.

A forgotten "city of water" underneath the famous Trevi district.

2300-year-old Roman road connecting the empire.

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."

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

A beautiful but toxic fountain of mercury.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

This hydrochronometer was invented by a Dominican monk and is a prime feature in this garden.

The oldest operating pharmacy in the world features 800-year-old recipes.

All that is left of this medieval castle is two towers, both of which now display a visible tilt.

This house certainly has a unique decor.

This castle was once the home of one of the most powerful women of the Renaissance.

A slingshot from this delightful collection is awarded each year to someone who has "pulled metaphorical slings in favor of the weak and marginalized."

These caves are home to a small church and were used to age cheese.

A striped 12th-century basilica sits in the countryside of Sardinia.

A landmark in the history of technology and computing is hidden in a tiny Baroque chapel.

A lonesome Moai stands in a small Italian town some 9,000 miles away from its Easter Island brethren.

Oakland's beautiful monumental cemetery.

A restored 1920s cascade stairway provides one of the best views of Oakland's Lake Merritt.

London's most popular recording studio, located in the capital's East End, runs partly on solar power and has played host to some of the world's biggest acts.