This monument to a veteran of the Mexican-American War is one of only two in Manhattan that serve as an actual mausoleum.

A Manhattan courthouse hides a small but scathing memorial to Holocaust injustice.

The one-time office of the architectural firm that ushered in the Gilded Age is now a Club Monaco.

Nope, not Washington Irving's house.

The notorious headquarters of a corrupt political machine.

A strangely angled West Village home is the only monument to an explosion that took the lives of three American revolutionaries.

New York's unstoppable progress turned this cemetery into the smallest burial ground in the city.

Named the fifth most beautiful building in America in 1885, this former courthouse boasts the best view in the Village.

New York City's smallest piece of private property.

This castle-like building in Manhattan helped destigmatize cancer in the 19th century.

The oldest living tree in Manhattan comes shrouded in sinister legend.

The former hotel where Tesla invented the radio.

The artist and New York City icon lived, worked and died in this converted carriage house owned by another iconic artist, Andy Warhol.

These historic buildings once housed the headquarters of one of the most infamous gangs of New York.

This wall on a street corner in Lower Manhattan has been a blank canvas for a rotation of renowned artists since the 1980s.

Walk over a 150 year old manhole.

Plot your trip through the city on the sidewalk.

School named after its beloved principal, killed in the cross-fire of a drug related shooting.

A massive forgotten storehouse from 1913 on the Brooklyn Waterfront has a spectacular view of Brooklyn.

Once home to the country's most gargantuan ships, this graving dock now waits for people to buy furniture.

A Red Hook dive bar that is holding onto its roots.

A modern zoetrope on the New York City subway.

This vacant church in the Financial District was once the heart of New York's first Syrian immigrant community.

This anonymous businessman sculpted in bronze became an enduring memorial after 9/11, and had been mistaken by rescue workers for a survivor in the rubble.