A series of fish plaques that are embedded in the malls of Ocean Parkway.

A commemorative plaque hides a door that leads down to the New York Public Library's underground book bunker.

The oldest private residence in New York City.

Millions of numbers carved in glass represent the tattoos forced upon victims.

These sculptures were designed to beautify this neighborhood when it was established in the 1940s.

Nine nice parcels of land along a flight path offer a quiet respite... until a plane soars overhead.

This Garden District mansion was built to be bigger and grander than its original owner's former partner turned rival.

The only subway station in the city that still makes use of gap fillers.

A riverfront park that both remediated and preserved its industrial past.

A once crucial portion of the Long Island railroad still lays abandoned, waiting to be turned into an urban park.

Queen Anne style apartment house built in 1886.

Constructed in the 1920s, this former pencil factory is now an office building.

Once a ferry dock, radio transmitter, and now a new Greenpoint park.

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

A 9-story, poured concrete structure which was used as a glue factory with an indelible smell.

Guerilla gardeners reclaimed this abandoned railroad land literally putting down roots.

Built in the 1920s, this co-op in the Bronx feels more like an Italian villa than a typical New York apartment building.

Amid skyscrapers and traffic exists this unique aquatic ecosystem.

The longest step street in the city.

Manhattan and the Bronx have been playing tug-of-war over this former island neighborhood for more than a century.

Surrounded by low rise buildings and partially converted into an auto body shop, this marble archway is the only vestige of a forgotten Manhattan estate.

This recently uncovered ad for Lindsay's run at Mayor in 1965 had been hiding for decades underneath a billboard.

This beachside town is home to a diverse nature reserve, multiple cays, and one of the three bioluminescent bays in Puerto Rico.

This colorful gate stands as an entrance to the walled city of Old San Juan.