America's first federal monument.

This stately building in Alexandria, Virginia was built by Freemasons to honor one of their most famous members.

The rogue roots are gradually consuming some of the historic marble grave markers.

Bubbling up from deep underground is the warm crystal clear water that fills the Warm Springs Pools, America's oldest spa.

The final resting place of two (or three) presidents, one vampire, and 18,000 Confederate soldiers.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

For almost a century, this East Village newsstand has served egg creams to beats, hippies, punks, and everything in between.

A veritable variety of odds and ends.

Tucked in the back of this amazing antique store is an important piece of medical history.

A temple belonging to the largest Buddhist order in South Korea nestled in the middle of New York City.

The competition: breathe deeply as long as you can.

You must take the A train... to the last active cemetery in Manhattan.

The last living thing to come out of the rubble after 9/11 is now a symbol of hope and resilience.

Rat sculptures try to infiltrate the Graybar Building in an architectural tribute to New York City's nautical history.

Hiroshima survivor on Riverside Drive.

One of the oldest Jewish cemeteries in the city, it is now overgrown with an urban forest.

19th century cemetery hidden in Brooklyn's Prospect Park.

A beautiful collection of architectural ornaments rescued from demolished New York City buildings.

Unrepaired walls from a 1920 anarchist bomb attack.

A Victorian cemetery in the heart of Brooklyn remains a popular mecca of morbid curiosity.

The end of the 4 Line is also the end of the line for 300,000 souls in one of NYC's most illustrious cemeteries.

Hordes of precariously balanced stone figures crowd the shores of the Hudson River.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

Detailed facade of a brownstone in Boerum Hill.