Small on the outside, big on the inside, this church is an astonishing act of visual deception.

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

The secret medieval communication system will whisk your words above the noise of the crowd.

One of the world’s smallest bars, just 13 square feet, is brimming with speakeasy flair.

This giant middle finger statue sends an unambiguous message to Italy's bankers.

A Milanese café entirely designed by the American director Wes Anderson.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

Architectureal fantasy quarter of Rome.

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

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."

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

This fantastical waterfall is hidden in a cave located in a cracked cliff.

Medicinal spa created from the mineral-rich runoff of a geothermal power plant

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

A 19th-century artistocrat's mansion, turned into a library, hidden in a modern library.

This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

The railway carts travelers to central Athens's highest peak, which offers stunning vistas of the city.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

The hallucinogenic center of the ancient world.

Dedicated to the European Sinti and Roma peoples murdered during the Holocaust.