A marvel of Byzantine engineering under the streets of Istanbul.

Hidden beneath a beautiful overlook you’ll find the history of the city depicted in comic strip format next to a pay toilet.

The haunting complex honors the millions of Ukrainians who died in the forced famine under Soviet rule.

The deepest metro station in the world.

One of the largest museums in Ukraine remembers the story of the German-Soviet War in iconic, brutalist style.

340-foot statue built to honour the Heroes of the Soviet Union.

A reconstructed medieval gateway that was the magnificent entrance to the capital city dating back to 1037.

Hanging within this medieval church are the bones of a beast allegedly slain by a fourth-century saint.

The small peaceful island off the Venice tourist circuit is where the city began more than 1,500 years ago.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

A copy of the famous statue can be found in this Florence piazza, along with one of the most breathtaking views of the city below.

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

Over 50 exquisite hand-painted Renaissance maps decorate a Medici storage room.

An artificial date palm stands as a memorial to Warsaw's Jewish community.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

Baroque celebration of the end of the Great Plague of Vienna.

Op-art architecture designed for happiness.

This easily overlooked memorial immortalizes the scars from the 1956 Hungarian Revolution.

The geographical center of Budapest is marked with a 10-foot-tall stylized zero.

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

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

This statue of a falling man commemorates a teenage martyr of the Hungarian Revolution.

This quaint Hungarian railway system is operated exclusively by children between the ages of 10 and 14.

A fake Transylvanian castle houses a cathedral of antlers.