This off-limits room in the National Library of France is home to a system of pneumatic tubes, once used to bring books to readers.

A haunting collection of the vanished and disappearing natural world.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

This massive library holds what was once the largest book collection in the world.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

These gigantic skeletons tower over visitors and provide insight into the creatures that once ruled over Ireland.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

This 1,300-year-old marker is one of the finest and most complete early Christian crosses in Scotland.

Where the sleeping monsters of Scotland's oil industry are left to rust.

Come for the oysters, stay for the priceless art honoring inventors across history and Scotland's favorite outdoor sports.

A castle in the Scottish Highlands has been continuously inhabited since the 1300s.

Overlooked by many, the two famous Scottish warriors guard the main gate of Edinburgh Castle.

Nestled amid the peaks and lochs of the Scottish Highlands, this inn and pub has played host to outlaws and ghosts.

Scotland's only funicular railway is also the United Kingdom's highest.

The taxidermy remains of the first mammal ever cloned from an adult cell are on display in Edinburgh.

A small island abbey is the final resting place of many medieval Scottish monarchs, including the real Macbeth.

Monty Python fans will recognize this abandoned mine as the Cave of the Killer Rabbit of Caerbannog.

On this stunning Scottish island, you can walk in the footsteps of dinosaurs.

This dramatic landscape hidden on the Isle of Skye looks as though you've stepped into the magical realm.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

These fantastically named natural pools look like something out of a Scottish myth.

The world's most charming instant portrait studio also happens to be its smallest.

A former factory now pays tribute to a local industry fueled by sardines.