Eighty million natural history specimens call this gargantuan museum home.

Catacombs turned marketplace.

Hear the quietest sound from across the dome.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

One part local history, 99 parts gruesome haunted house.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

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

Where commuters walk through remnants of an ancient Greek necropolis.

150 or so scrounged-up lamps, chandeliers, and lanterns light up this alley in central Athens.

This striking sculpture of Icarus honors Greece's fallen flyers.

This mystical orb covered in strange symbols is thought to have been used in ancient Greek magical rituals.

A restaurant devoted to "trouser grip" wrestling, an ancient form of Viking wrestling that is Iceland's national sport.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

Three columns of volcanic rock shoot out of the ocean.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

Iceland's tribute to its thankless civil servants.

This stunning concert hall has become a symbol of Iceland's national recovery.

Pompeii's less famous neighbor is still revealing her secrets.

The Neapolitan Cult of the Dead still cares for the skulls at this mini-Fontanelle.

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.

As can be expected from a centuries old church built in a canal city, the undercroft of this house of worship is beautifully flooded.

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.