A daily replay of the experiment that proved the rotation of the Earth.

The sounds of the world's largest fully functioning pipe organ dazzle shoppers at a Philadelphia Macy's.

This elaborate towering structure was once famed for its revolutionary height.

Instruments, apparatus, and rare books all relating to chemistry and its related sciences.

Dr Barnes' $25 billion private collection of art and arboretum.

The first American department store, and home to the largest operating musical instrument in the world.

A rare view of a preserved Victorian science museum.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

The bank that helped fund the Mexican-American War and the purchase of Alaska met its downfall after helping Augusto Pinochet launder money.

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

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

An overlooked memorial honoring the local Washington residents who died in World War I.

Look closely and you’ll notice that the color changes a third of the way up the tower.

A historic arena where the Beatles played their first concert in the U.S.

A small triangle of DC grass is the final resting place of one of Sonny and Cher's songs.

The only Civil War battle in Washington D.C. took place near this highest natural point in the city.

A museum cafe showcases Native American dishes and indigenous ingredients from across the Western Hemisphere.

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

The most accurate timepiece in the world.

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

A super-sized promotional trick that is now a D.C. landmark.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.