Eastern Bloc nostalgia, anybody?

A striking symbol of the Bulgarian capital.

This building has two facades of clashing architectural designs.

Sofia's legislative center is continuously reinventing itself.

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

The silly symbol for an underground protest group is now scattered around the city.

A 90-ton, gravity-defiant steam locomotive shoots for the skies in this bizarrely beautiful public artwork.

Extremely famous in his native country, this Cracovian painter is all but unknown beyond Polish borders.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

Real bones which are said to have belonged to a Polish dragon.

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

A huge enchanting public park just outside the ancient walls of Rome.

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

Breathtaking and huge 430 year old maps of Italy.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

Also known as the Square Colosseum, this building is a prime example of fascist-era rationalist architecture.

One of Catholicism's four major basilicas has a series of papal portraits that are said to predict the end of the world.

One of the four sanctuaries of Rieti's Holy Valley was the site of the first living nativity scene.

The final resting place of the poets Shelley and Keats.

The yawning maw of this pagan visage is said to bite off the hands of liars.

The US Navy's only submarine museum is also home to the world's first nuclear submarine.

This monument on Breed's Hill proves that one of the most famous battles of the Revolutionary War is misnamed.

The first bridge observation tower in the U.S. offers one of the best views of Maine.