Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Now abandoned, the first public health hospital in the U.S. saw more than one million immigrants from around the world.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

The only Bahá'í house of worship in North America and one of only a handful worldwide.

The United States’s oldest funicular railway glides up and down a steep Pittsburgh street.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

A favorite Paris bar for U.S. expats, including Gershwin, Hemingway, and James Bond.

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

The yawning maw of this pagan visage is said to bite off the hands of liars.

Enjoy an overnight at an old haunted B&B site of the Borden family murders.

A very classy 1920s-era bar right in Grand Central Station.

A sculpture made of 10 Cadillacs as a monument to the “Golden Age” of the American automobile.

Sniff the Titan Arum's rotting flesh.

The "Seinfeld" diner.

Mysterious 500-year-old tapestries depict a unicorn hunt.

The second oldest continuously operating bar in Louisiana.

The trials and tribulations of marking Poe’s grave.

The only rotating bar in New Orleans has been slowly spinning since 1949.

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

One part antique store, one part curiosities hodge-podge.

Famously misunderstood wonder of the ancient world

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

The oldest cemetery in New Orleans, resting peacefully for over 200 years now.