New York's southernmost subway station is whimsically wavy.

A memorial marks the library lobby where Langston Hughes' ashes are buried.

The largest collection of historic military firearms in the United States.

Memorial built in 1922 in remembrance of WWI casualties.

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

The only remaining piece of hull of the most decorated US ship of WWII is this giant name plate.

Outstanding taxidermy dioramas showcase the grandeur of the continent's wildlife with spooky realism.

One of the only single-person private gravesites in New York City.

A replica of a 7th-century church hides in plain sight in the middle of the concrete jungle.

The way these carnivorous dinosaurs are posed is an homage to a classic work of paleoart.

This striking arch, one of the first architectural elements constructed in Prospect Park, was recently restored to its original glory.

The first pet cemetery in the United States.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

Don't get it twisted: This is the oldest pretzel bakery in the United States.

This old estate is a remnant of when the Bronx was a popular summer destination for wealthy New Yorkers.

Plymouth's huge yet little-known memorial to the Pilgrims.

A monument stands to the famous suffragist who penned the declaration for women's equal rights, including the right to vote.

Small monoliths of several varieties of stone sit alongside a wooded path in the Bronx.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

A memorial to the first person killed by a motor vehicle in the Western Hemisphere.

Hidden behind a gate in Greenwich Village is a little farmhouse that once served as the writing studio of a bestselling author.

Site of the first pathological and bacteriological research facility in the United States.

Oldest surviving example of a Dutch saltbox frame house in America.

An eccentric priest's tribute to George Washington, this chapel tells the story of the American Revolution.