This sandstone mansion was the home of two of Oregon's most important pioneers.

10,000 flowered plants bloom in the City of Roses.

"the sweltering inhabitants of Charleston and New Orleans, of Madras and Bombay and Calcutta, drink at my well . . . The pure Walden water is mingled with the sacred water of the Ganges."

A historic bridge with a lovely acoustic anomaly.

The headquarters of one of the world’s longest-running humor magazines bears a noticeable resemblance to a head wearing a Prussian helmet.

This supermarket is suspended 25 feet above an interstate highway.

This pun was simply waiting to come to life, and one defense contractor made it so.

The largest cemetery for enslaved people in Loudoun County was almost lost to history, if not for the research of a minister.

The Aldie Gristmill was once the largest factory of its kind in Loudoun County.

Named for a Greek oracle that interpreted the words of Zeus, this beautifully-restored manor home was once home to the architect of the Marshall Plan.

One of the Treasury Building's original columns now sits as a garden monument in the middle of a busy military base.

This marker at the entrance to the Humphreys Engineer Center honors the former Chief of the Army Corps of Engineers.

A piece of the Ludendorff Bridge, also known as Remagan Bridge, calls this military base home.

A perfect circle of 24 mysterious holes dates back to prehistoric times.

This beautiful Miami garden was designed as a laboratory for tropical plants.

Neglected resting place of some of the city's early luminaries—and a woman encased in concrete.

The little-known final resting place of one of America's greatest writers.

A giant light 13 feet high shines near Thomas Edison's old Menlo Park lab.

This Manhattan skyscraper is a reminder of the brief but glorious age of urban air taxis.

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

New York's oldest and possibly grandest keeper of books.

Curious crustaceans support an obelisk from ancient Egypt that now stands in modern-day Central Park.

This huge work of functional public art replaced a landfill in New Jersey's Meadowlands.

Try not to get slimed in Tribeca.