A 19th century library favored by Edgar Allan Poe and H.P. Lovecraft, known by locals as "the Ath."

A Nesting Doll of Churches.

A rather vulgar example of the transition from Latin to the Italian vernacular.

Its interior is adorned with some of the best examples of early Christian mosaics.

An alchemist's "magic door" stands in the middle of a Roman park.

A wunderkammer of curious objects and intriguing art nestled within a hub of ancient Roman sites.

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

Believed to be the remains of the lost Temple of Minerva, this nymphaeum has been known by its misnomer to this day.

Stone memorial that's said to predict the death of the pope and the site of the Cadaver Synod.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

This hydrochronometer was invented by a Dominican monk and is a prime feature in this garden.

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

As can be expected from a centuries old church built in a canal city, the undercroft of this house of worship is beautifully flooded.

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.

The underground sanctuary of a mysterious ancient cult.

At the crypt of St. Mary of Eulogies and the Dead you are left alone to ponder mortality among piles of skulls.

Four metal statues of massive animal penises stand outside the university's Animal Sciences building.

This historic headstone is said to mark the final resting place of a doubly-dead white witch.

This kitschy curio wonderland is full of fake animals, teak tables, and a cacophony of random bric-a-brac.

In memory of the 110 victims of ValuJet Flight 592 that crashed in the Everglades.

A failed, un-built suburb that has been going feral for decades.

These crumbling foundations are all that remain of the once-stately 1840s manor that gave the town of Bradenton its name.

The third tallest lighthouse in America once guided author Stephen Crane to safety.

Located within a historic park, the beacon is the oldest standing structure in Miami.