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

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

Take an underground boat ride through a former hydraulic raceway that was built in the late 19th century.

Gilded heaven for philatelists and architecture freaks, still in full working order despite sitting atop tremulous ground.

These winged Maya figures are the subject of speculation and conspiracies.

Tucked along a river are enigmatic stone carvings created thousands of years ago.

These subterranean models show Mexico City's central square during three different eras.

A grand entrance to one of the world's smallest Chinatowns.

In Coyoacán, a pair of coyotes crown a public fountain in reference to the ancient Aztec name of the borough.

The Mexican painter Diego Rivera created this unusual museum to display his collection of pre-Hispanic artifacts.

These haunting ruins of a 700-year-old Prehispanic city have witnessed centuries of wars and massacres.

Frida Kahlo's childhood home, now a museum of her life and works.

This historic patch of real estate offers a glimpse of colonial Boston.

Millions of numbers carved in glass represent the tattoos forced upon victims.

A centuries-old church stands as a testament to Boston's "father of architecture."

The site of Paul Revere's historic two lantern warning.

Historic Hull Street was actually the first street with a proper name in the Boston area.

Narrowest house in Boston.

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

This ambitious father and son team reigned supreme over the North End, and witches, for many years.

The tomb of Increase Mather and his son Cotton, influential colonial ministers obsessed with the occult.

One of the indelible moments of the American Revolution took place at this location.

These items are all that remain from the room used by the author during his second tour of the U.S.

A former waterfront market is now in the center of town due to some interesting Boston engineering.