The City Concealed | THIRTEEN

The High Bridge, New York City's oldest standing bridge, spans the Harlem River at 173rd Street in Manhattan. It officially closed sometime during the early 1970s -- the Parks Department, mysteriously, isn't certain of the exact date -- but remained open for ranger tours until the late 1990s, when the gates were shut to all but Parks employees after engineers discovered structural flaws.

The Park Slope Armory was built in 1895, designed by William A. Mundell for the 14th regiment of the National Guard, also known as the Brooklyn Chasseur. The regiment was founded in 1847 and has origins dating back to colonial times.

Before we knew about the Greenbelt, we were looking for the Heyerdahl House, the ruins of an 1800s stone home in Bucks Hollow. Following directions found online, we made our way to a trailhead and proceeded to get lost in the woods. After about an hour of hiking through a forested swamp still wet in late spring, we realized that we didn't need the house. The trails were special enough on their own. Secluded in the woods with nothing but trees in sight or earshot, we were impressed to find a place like this in New York City.

An overgrown access path behind Hinchliffe Stadium leads into what would have been right-center field. The vastness of the U-shaped stadium from that vantage suggests not a baseball or football stadium but a raceway. These ruins tell the story of an era long gone.

Ridgewood Reservoir is one of those places that defies the common imagination of New York City. A lake sits surrounded by reeds and two massive basins, each with its own habitat. Dirt paths lined with iron gates from previous centuries surround the basins, but this all hides within a chain-link fence that cuts off access. The fence is a patchwork in constant development, telling the story of repeated entries with wire cutters. A few people might circle the outer fence's road on foot or bicycle, but for the most part the site is empty.

Kehila Kedosha Janina, tucked between a Chinese merchant and a glass shop in New York's Lower East Side, is the last remaining Romaniote synagogue in the Western Hemisphere.

We stood in the basement of 169 W. 133rd Street in Harlem shining a lantern at the rotted walls, saturated ceiling panels, and corroded fixtures. A lawn chair surrounded by discarded soda bottles occupied a corner of the room where the bandstand once stood. Who knows how they got there, or who would've wanted to spend time in so dank a space. Eighty years ago the Nest would have been throbbing with music, drinking, and dancing. The day we visited with our guide, David Freeland, author of Automats, Taxi Dances, and Vaudeville: Excavating Manhattan's Lost Places of Leisure, we found the space as silent as a recording studio. Mushrooms sprouted out of the cold muck on the floor.

North Brother Island lies in the East River, between The Bronx and Queens, just west of Rikers Island and directly under the flight path of departing jets from LaGuardia. It was once the site of Riverside Hospital, a tuberculosis facility later converted to GI housing after WWII. Previously, it was home to the infamous "Typhoid" Mary Mallon during her years of quarantine. Throughout the 1950s, the city operated a drug rehab center for adolescents there, but the hospital closed in 1963, and North Brother was abandoned. Nature slowly reclaimed the island. Today North Brother Island is a protected heron habitat, owned by the Department of Parks and Recreation. Access to the island is extremely limited due to the sensitivity of the bird-breeding habitat.

Fresh Kills Landfill on Staten Island was New York City's primary landfill from 1948 to 2001. Thousands of tons of daily garbage composed the largest man-made structure on Earth. In 2001 the landfill was finally closed, with a brief reopening to accommodate the World Trade Center wreckage. Since then it's been the site of Freshkills Park, a 30-year project to cover and slowly open parts of the former landfill.

The United Palace is a fantasy, an architect's dream of excess, embellishment, and more and more gold paint: a Greek goddess presides over a hall lined with meditating Buddhas, Indian ascetics share the wall with fat Renaissance cherubs. Nothing really makes sense here, but it all comes together completely.

The Hunterfly Road Houses of Weeksville are the discovered remnants of a free African-American enclave of urban trasdespeople and property owners.

Jack Putnam is the South Street Seaport Museum's historian. Occasionally he leads tours of the upper floors of the old hotel, but visitors are rare. The artifacts that remain - century-old wallpaper, delicate plaster, and rickety wooden planks - are too fragile to allow frequent foot traffic.

Brooklyn Navy Yard is one of NYC's largest pieces of intact - though decaying - history. Sprawling over nearly 300 acres, it has current industrial tenants, and plans are in the works for adaptive reuse projects for some of the buildings.

A lifelong Staten Islander, Doug Scwartz has been creating rock sculptures on the beaches of Mount Loretto State Park for over a decade.

Green-Wood Cemetery is best known as the final resting place of famous New Yorkers like Boss Tweed, the Steinway family, and Leonard Bernstein, but it's also a treasure trove of hidden sculpture and architecture.