A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

There's a crumbling old mansion inside the Smithsonian National Zoo.

When it opened during the final years of the embargo, all the drinks and cigars were free.

Giftshop catering to cryptozoologists and anyone with a sense of humor.

A hidden passageway now marks the site of an assassination attempt on Ronald Reagan that some say broke a 140-year-old curse.

You could be standing at the site of one of D.C.'s most fatal tragedies and not even know it.

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

The first memorial dedicated solely to the Black troops who fought for the Union.

A massive art collective tries a new take on Brooklyn's DIY music scene—by making it fully legal.

A museum devoted to bringing to light forgotten or neglected histories through exhibitions, education and public programming.

The highest rapid transit station in the world.

Before online banking and smartphone apps, there was "commuter banking" in the subway in Downtown Brooklyn.

The return of something once considered a basic part of life.

Once a flowing stream and where the USS Monitor, the world's first ironclad, was built and launched.

The childhood home of one of America's greatest unsung troubadours still stands in a much changed Brooklyn neighborhood.

Church featuring "high Victorian gothic" architecture.

While it now takes more than a dime to open an account this historic Brooklyn bank still displays the opulence of the gilded age in which it was built.

New York's southernmost subway station is whimsically wavy.

Lehigh Valley barge No. 79 still gets tugged along - but now it houses a museum and unusual performances.

The humble fort that saved Washington.

One of the few Glatt kosher delis in the United States is a cornerstone of its Hasidic neighborhood.

Where infamous mobster and leader of Murder Inc. Albert Anastasia made his home.

Brooklyn's most iconic restaurant, resurrected.

Spike Lee's provocative film is officially honored right where it was made, the first time a work of art was used as a secondary street name.