King Ludwig I's collection of beautiful women.

This abandoned amusement park was built on a site with a dark history.

The world's longest wildlife overpass provides Hilversum's critters with a safe alternative to trying their luck on the roadway.

The somber sculptures commemorating Irish Famine on the river Liffey in Dublin.

Giant, friendly pelicans in Central London, the most unlikely of places.

Crammed into a Baltimore row house is an oddities shop that sells everything from skulls to dead insects.

Wedged between two buildings at the Great Ormond Street Hospital is this secret music installation.

Semi-precious Blue John stones have been mined in this cavern system for centuries.

A mythical bird etched into the face of a rock doubles as the mascot for a nearby school.

This little-known collection holds everything from "Dracula" notes, to the manuscript of "Ulysses," to the forged works of Shakespeare.

Enormous lake at the bottom of a unique cave system.

On Japan's Tashirojima Island, cats are king.

An underwater city for the dead.

A collection of collections ranging from dentistry to minerals.

The fossilized remains of ancient California redwoods.

An artsy hidden staircase leads to breathtaking views of San Francisco.

Home with Gothic windows featured in a famous painting.

A rococo retro-futurist future-rustic vernacular between yesterday’s tomorrow and the future that never was.

A mailbox that saved a nature reserve.

An arsenic-filled pool in the Grand Canyon takes on the appearance of a giant, overflowing pumpkin.

An abandoned castle owned and ignored by Masons carries a cursed history.

Nursery with extensive collection of flesh-eating plants operated by the author of "The Savage Garden."

The city is full of whimsical portals to another world.