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

The largest known Ancient Egyptian obelisk.

Known as the Sistine Chapel of Egypt, this tomb houses some of the most well-preserved paintings in Egypt.

These Egyptian statues have survived for 3,400 years and were an acoustic wonder of the ancient world.

This subterranean funicular is one of the world's smallest subways.

This daunting 1st century fortress was purportedly the site of one of the most dramatic revolts of the Jewish-Roman wars.

The home of the Dead Sea Scrolls is an abstract modernist dream.

The bluer than blue waters in these natural Israeli caves are reached via the world's steepest cable car.

Christ's blood preserved in a Belgian town.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

This museum covers 10,000 years of Pre-Columbian Latin American history.

You have to know where to look in this rather ordinary-looking square to find hints of its past as a dissidents' cemetery.

A whimsical bridge adorned with decorative dragons.

This dazzling Buddhist temple was constructed from over one million ceramic tiles salvaged from a British shipwreck.

A spherical "micro-nation" in the heart of Vienna.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

The beautiful baroque library of the Hapsburg empire.

The metal leaves on this tree are engraved with the names of Holocaust victims.

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

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

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

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

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