A medieval weapon rumored to have been used by the brilliant poet himself.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

A new sculpture calls attention to climate change in the centuries-old city it threatens.

A magnificent waterfall is also home to the remains of a Roman hydraulic engineering system.

One of the most important yet well-hidden museums dedicated to the history of medicine.

The martyr's wax-enhanced skeletal remains lie preserved in a glass case in the Santa Maria della Vittoria in Rome.

One of several skulls claiming to belong to the beheaded St. John the Baptist is on display at this Roman church.

Jesus' footprints and the first catacombs in the world.

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.

Site of a former hidden treehouse in New Orleans.

This macabre shop, filled with art, oddities, and taxidermy is hidden in the heart of the French Quarter.

The only home of the famous French impressionist painter open to the public is now a museum and bed and breakfast.

A house of courtship where the Jazz Age's most storied lovers got their start.

A 19th-century shrine covered with prosthetic body parts as votive offerings.

The restaurant keeps a hidden séance room on the second floor and reserves a table for the spirit of the former owner each night.

This knobby, drooping New Orleans oak is a favorite place both for climbing and for meeting giraffes.

A theme park that suffered massive flooding during Katrina was abandoned, and now proves irresistible to trespassing explorers.

Like stepping into a spooky fairy-tale, this shop carries the dark ideas of artists and other makers.

One man’s hobby is another man’s world of metal wonders.

The 340-year-old house that inspired the classic Nathaniel Hawthorne novel.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

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

Eighteen miniature death-scene dioramas.

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