Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

This large copper bolt represents the benchmark for measuring sea levels in most of Europe.

Tucked in the back of a flower shop, its collection details the fascinating history of the Netherlands's iconic symbol.

This Prague museum collects brutalist relics and memories from the country's former Soviet rule.

A self-proclaimed libertarian micro-state on a tiny bit of disputed territory between Serbia and Croatia.

This medieval mountain town is also known as the "Village of Streams."

A narrow opening between the mountains of the Amalfi Coast creates a scenic hidden beach.

Amalfi's pre-industrial history is slowly being engulfed by the lush vegetation of the Ferriere Valley.

This former railway facility is the oldest in Slovenia, and now houses a museum showcasing the history of steam locomotives.

This scale model of our solar system hid in plain sight for years before a physics team sought out all the planets.

Once a state-of-the-art tuberculosis treatment spa, these ruins are now ruled by paintball players.

The remains of a sunken military ship wreck visible through clear water.

In northeastern Poland, the ruins of a massive granary overlook the Narew River.

Mysterious craters may have been home to an ancient cult.

The neon signs from Las Vegas' past find their final resting place at this unusual graveyard.

Most-visited and most-photographed slot canyon in the American Southwest.

Among the ostentatious rococo ornamentation of this church, an image of death cuts the life-thread.

One of the most easily accessible examples of the rare 1960s UFO houses.

A stairway to heaven, or to nowhere at all.

The forgotten tomb of the Peruvian rubber baron who was the inspiration for Werner Herzog's epic film "Fitzcarraldo."

This small oxbow lake has rare giant river otters and some Seussian-sounding birds.

A painting in the historic Cathedral Basilica depicts Jesus and his disciples dining on a traditional Peruvian menu.

Love is in the air along the small street in Brooklyn.