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

A rare view of a preserved Victorian science museum.

An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

Macabre symbols of death and mummies on display set the tone of this Italian purgatory church.

The curious underground history of keeping Paris clean.

A unrivaled and rather horrifying collection of wax dermatological models.

The largest medical and anatomical collection in France lies hidden from the public.

Known as the "Dodo Manège," this carousel features a herd of animals that have disappeared—or may be gone soon.

Statue of death tucked in the University of Medicine courtyard.

This museum houses an imposing skeleton army comprised of creatures great and small.

Paris' fabled purveyor of exotic taxidermy and natural history curios.

Stripes of human ashes cover a back lawn in the most sought-after burial grounds in Paris.

A haunting collection of the vanished and disappearing natural world.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

This church devoted to Mexico's "dead saint" is a festive celebration of a formerly hidden religious figure.

If you can look past the nearby sewer pipes, this urban sinkhole grotto is a mini-paradise.

These azure waters were thought to lead to the Mayan Underworld.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

Every equinox this Maya pyramid puts on a spooky ancient light show.

A hidden treasure of an abandoned city lies deep in the jungles of Campeche, Mexico.

This church, buried halfway in lava rock, is all that remains of a Mexican village destroyed by a volcano.

A jewel of the Mexico city skyline now slowly crumbles after surviving an earthquake.

Diego Rivera's massive tiled fountain and failed infrastructure project.