The once forbidden "secret cabinet" of erotic art from excavations of Pompeii and Herculaneum.

An exhibit of items from the mental institution where Mary Todd Lincoln lived after her son conspired to have her committed.

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

Solving a 60-year mystery finally gave a name to the young woman known only by the color of her clothes.

The first spinning jail built in the United States is the only one that still turns.

The site of a 19th century "dream city" that almost rivaled Chicago before being swallowed by the Indiana sand dunes.

A metal ring in the middle of the road marks the exact spot where the Soviet satellite crash-landed in 1962.

Once thought to be the fabled Holy Grail, it is now known to be an oil lamp.

Part of a secret 1970s nuclear defense program is now open to the public.

Where a guard killed nine German prisoners during one of the worst 20th-century POW camp massacres in U.S. history.

An eccentric aristocrat brought these Australian natives to their current Scottish home.

This little gem of Spanish Colonial architecture has been abandoned since the 1950s.

This largely forgotten piece of Cold War history stands hidden in the woods just north of the Mississippi Gulf Coast.

This English medieval castle is where King John died of dysentery.

Edison's cast-in-place concrete houses were a failure, but way ahead of their time.

The centuries-old trees lining both sides of this dirt road may become Madagascar's first natural monument.

Visit the home of Sweden's beloved fictional character, Pippi Longstocking.

More than 21,000 images fill this overlooked gem of a prehistoric site.

This off-the-beaten-path abandoned town is a relic of Montana's silver mining boom.

An Industrial Revolution-era public work that purified water using nothing but sand.

The oldest surviving botanic garden in the United States.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

The land is full of geologic eye candy, such as otherworldly spires, mushroom-shaped hoodoos, and prehistoric fossils.

One Confederate statue that accurately reflects the ugliness of its subject.