The world's largest Holstein cow.

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

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

This unacceptably tall building was the real reason for Washington, D.C.'s skyscraper ban.

A rotating cast of guys and dolls in front of a Washington, D.C. building.

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

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

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

Through the decades, Black music stars have performed at this historic hub for music and the arts.

More than 500 unique and specially designed cases collected by D.C.'s "Harmonica Case Man."

This poor little statue is the most vandalized memorial in Washington.

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

A gorgeous mural outside a beloved D.C. restaurant pays homage to famous Black Americans.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

During the Industrial Revolution this “Temple of Invention” was full of intricate miniature machines and gadgets.

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

A painfully obvious spy house sits right across the street from the Russian Embassy.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

A wondrous old library overlooking the nation's capital.

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

A historic neighborhood church is reborn as a psychedelic arts collective.

This grand gothic brewery has been pumping out suds for over a hundred years.