Thousands of coffin-like pillars make up this controversial Holocaust memorial.

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

Sofia's legislative center is continuously reinventing itself.

A striking symbol of the Bulgarian capital.

A gigantic statue of a Russian soldier watches over the ancient city of Plovdiv, a prominent reminder of the Soviet period in Bulgaria.

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

Where Venice's gondolas go for a tune-up.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

Two stone columns flank the grand Venice square, but there were supposed to be three.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

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.

Renaissance hospital featuring a rotating door into which unwanted babies were dropped.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

This Roman arch marks the location of an ancient gate at one of the Seven Hills 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.

2300-year-old Roman road connecting the empire.

Rome’s legendary peephole vista is also a former Crusader stronghold.

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

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

One of its engravings is believed to be among the first representations of medical and surgical instruments.

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