A more than 260-year-old crypt built on Boston's oldest English burial ground.

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.

This landmark cemetery in Boston was created more than 300 years ago.

This Boston medical museum features the skull of the famous medical case of Phineas Gage.

An enormous, inside-out glass globe built in 1935.

San Francisco's first World's Fair, dedicated to the wonders of California.

A free, public museum dedicated to the fascinating science of sight.

With the touch of a button, you can read a randomly selected short story.

Fonts are born and bred here at the oldest letterpress type foundry in the United States.

A library and museum dedicated to typography.

This shop and studio is dedicated to the art of the book, from letterpress to bookbinding.

The oldest burial ground in the city, final resting place of city founders, Ohlone natives and murderers alike.

The remains of a ruined mansion memorialize the 1906 earthquake.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

A psychedelic labyrinth on the San Francisco bay.

A huge musical instrument played by the ocean.

Live long and prosper in Tennessee.

These ancient ritual mounds are our best window into the culture of the ancient Mississippians.

More than five miles of underground passageways.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

These eerie outliers of the lightning bug family glow a mysterious blue color.

Knoxville’s architectural icon was the symbol of the 1982 World’s Fair, even catching the googly eye of Bart Simpson.

Better known as the "Body Farm," this unique research facility has been studying how human bodies break down since the 1980s.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.