Go inside to really appreciate this 500-year-old technological masterpiece.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

This whimsical fountain pays tribute to Toronto's four-legged friends.

This massive, ancient stone was disassembled and then put back together again.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

This medieval cathedral houses stained-glass windows featuring saints and pretzels.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

Romania's triumphal arch looks out over Bucharest.

Sofia's legislative center is continuously reinventing itself.

Founded in the 4th-century, the town of Pernik plays host to the Surva Carnival⁠—a magnificent display of masked Kukeri dancers.

Outstanding, eerie frescoes and decorations fill this 19th-century monastery.

This ancient theater, restored in the 20th century, lives on as a venue for dramatic and musical performances.

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

The second-largest Jewish temple in Bulgaria was deserted after World War II, seized by the communist government and then abandoned again.

This historic black and white monastery is one of Bulgaria's architectural jewels.

This tiny Bulgarian town offers a stunning location in the mountains and a storied history.

This massive concrete sculpture is said to be the heaviest communist monument on Earth.

Bizarrely shaped rock formations in northwest Bulgaria come with equally bizarre legends.

An extraordinary collection of scientific instruments - and Einstein's chalkboard - inside the world's oldest purpose built museum building.

Ancient Egyptian wigs, South American feather headdresses, a bounty of anthropological artifacts in Oxford.

A vast Communist-era exhibition space in the Bulgarian capital.

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

Eastern Bloc nostalgia, anybody?