An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

A 16th-century horror show built in a lovely Italian garden.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

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

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

This knockout museum lies in a sleepy corner of London.

This elaborate Byzantine-style building was designed for a not-so-pretty purpose.

Tombstones and enigmatic inscriptions hide within a vault beneath a popular London arts venue.

A Victorian park cemetery, standing on the site of what was once the Great North Wood.

The mystery of the Putim Ossuary involves a tricorn hat.

The bones of some 7,000 soldiers killed in the historic Battle of Solferino are stored here.

A 1,000-year-old church holds the bones of the Christian martyrs who died hiding inside it.

Buried for centuries, this hidden cellar is all that remains of London's medieval Whitefriars Monastery.

This beautiful Victorian ironwork masterpiece was built to keep London from smelling like poop.

The sixth of London's "Magnificent Seven" cemeteries, and a source of unlikely inspiration to Beatrix Potter.

Repository for more than 22 million pickled specimens.

A historic London cemetery now serves as a nature park incorporating gravestones & memorial statues.

A cluttered and astounding collection of antiquities and curiosities.

In this cobwebbed old operating theater, you can practically hear the screams of the unanesthetized patients.

The anatomical-pathological collection of a man who changed surgery.

Taxidermied animals galore, by appointment only.

A wonderfully eclectic Victorian aquarium lies in the basement of the Horniman Museum.

These morbid carvings remind churchgoers of the inevitability of death.

This landmark church concealed a crypt packed with bones that was discovered thanks to the London Blitz.