The two writers famously didn't come to blows over the Oxford comma.

The remote outlaw hideout of Jesse James, Butch Cassidy, and the Sundance Kid.

The huge collection of paintings of the American West is one of Denver's best-kept secrets.

A piece of crumbling highway infrastructure was repurposed as a high-tech facility for testing racecars.

The second-longest continuous wall on the planet protects a hidden secret in the deserts of India.

This icon of the Atomic Age now lays dormant.

Home to items never before seen by the public.

Eighteen miniature death-scene dioramas.

Where condemned pirates met their grisly end at the gallows on the River Thames.

A painfully obvious spy house sits right across the street from the Russian Embassy.

Metal water storage tank turned ethereal concert hall.

A humble garage, world-famous for being the epicenter of a technology revolution.

The "Mona Lisa" of funerary art.

An unassuming secret door once led to a legendary watering hole.

A mysterious spirit totem at the edge of Navajo lands.

A 19th century artistocrat's mansion, turned into a library, hidden in a modern library.

Over 50 exquisite hand-painted Renaissance maps decorate a Medici storage room.

This might just be the TARDIS of bookstores.

Someone loved this song enough to carve all of its lyrics onto a tree trunk in a Berlin park.

Street artists transformed an abandoned air vent into the beloved Star Wars robot.

A cheeky reminder about the value of art dangles above one of Olomouc's busiest streets.

Thirty creepy ghosts now inhabit this decaying 14th-century church.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

In a dry, neglected cemetery lies the unassuming grave of a soldier vilified in life but celebrated in death.