This modern, multimedia museum takes visitors on an evolutionary journey back in time.

This Croatian fairytale castle is slowly falling apart thanks to years of neglect.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

A massive bridge forms part of an aqueduct that was deemed an architectural wonder of its time.

Nobles would stage mock naval battles on this large lake at the Royal Palace of Caserta.

A star-shaped fortress town fort built in the geometric model of the Renaissance utopian city.

This strange bovine gargoyle is said to have been put in as a passive aggressive form of revenge.

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.

Water and windows define this defensive Italian well.

This beautifully designed star-shaped fort was the premier defense system of the late 1500s.

The world's most important buildings shrunk to a tiny size.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

A floating cat sanctuary on an Amsterdam canal.

Moscow's imposing monument to the Space Age.

Museum celebrating the achievements of the Soviet space program.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

This statue dedicated to the story of a Flemish boy and his dog was relatively obscure in Belgium, but a cult sensation in Japan.

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

Italian poet Dante Alighieri is entombed in this small mausoleum in Ravenna, and his hometown of Florence has never been too happy about it.

A two-way chairlift system between Zugliget and the highest point in the city.

The remains of an ancient Roman city are hidden underneath Bologna's beautiful public library.

Legend has it this fountain built to symbolize the Pope’s power hides a strange secret concerning Neptune's manliness.

Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

A small window on Via Piella offers a lovely and rare peek at Bologna's lost canals.