A limestone grotto where daylight filters in from below and turns the water a beautiful turquoise. Also home to a small underwater nativity scene.

Used as an example in one of the first dictionary entries for "museum" in 1706.

The spot where three Protestant clergymen were burned at the stake during the reign of "Bloody Mary."

Once one of the largest rooms full of books in the world, this bookstore basement is still a treat for bibliophiles.

One of Europe's oldest libraries.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

The final resting place of the poets Shelley and Keats.

The Italian revolutionary's legendary wife is portrayed on horseback waving a gun and holding her child in this memorial on the Janiculum.

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

Breathtaking and huge 430 year old maps of Italy.

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

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

Brass cobblestones mark the places where individual Holocaust victims were taken from their homes.