This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

This gallery commissioned by Cardinal Spada is known for its magnificent optical illusion.

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

This is the oldest Roman-made bridge in the city still existing in its original state.

"Holy Wisdom" overlooks the city that became its namesake.

A striking symbol of the Bulgarian capital.

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

Plaques celebrating Lithuanian writers freckle a wall of this picture-perfect path.

This micro-nation may be some sort of prank, but its constitution sure seems official.

A preserved oak tree about 3,500 years old found in Riga, Latvia.

The reconstruction of this prominent building fulfilled a long-written command.

An abstract monument to a symphonic composer.

A subterranean house of worship carved right out of the bedrock.

These enormous, stern-faced statues greet visitors with lanterns, and sometimes costumes.

A trio of giant wooden megaphones turn up nature's volume in this Estonian forest.

This Estonian watchtower looks like a big tree with two giant bird nests on it, complete with a "golden egg."

A wooden statue of an Estonian pagan god and King of the Setos stands atop a sacred hill.

This peculiar border irregularity is the only way to legally enter Russia without a visa.

Its collection offers a glimpse into the Russian Old Believers' centuries-old way of life.

This unique eatery offers a taste of Estonia's "Onion Route."

Built to ward off Napoleon's army, this city-sized abandoned Russian fort is now perfect for urban exploration.

Also known as the Blue Church, the building was consecrated to the daughter of Andrew II.

No one knows the origin of this creepy little stone man with an oversized phallus.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.