The secret is out: New York City has some of spread across its five boroughs. OK, you already knew that. But just because you're familiar with the Met and MoMA and other household names doesn't mean you know everything about them. (How could you? Their collections comprise millions of works of art.) We've selected a few lesser-known aspects of the City's top art spaces to highlight, alongside some museums that don't always get the same due as the attractions on every visitor's must-see list. Read on for details., MoMA PS1 Set in a former school (aka Public School 1), this , located in Long Island City, Queens, puts on contemporary art displays that sometimes challenge the definition of what art is. Case in point: Head to the basement "gallery" of the building to see Saul Melman's transformation of the double furnace that once heated the place—the artist having stripped it down and then covered the boiler and pipes in gold leaf. Function, meet form.Graffiti on the , The Met Fifth Avenue The temple is set apart from the rest of the 's exhaustive collection in a number of ways; most notably, it's protected by a watery moat in its own purpose-built gallery, added on to the Met in the 1970s. It takes a sharp eye to see another distinguishing mark: the graffiti on the piece—mostly from the early 1800s—carved into the limestone bricks during the days the temple sat on the banks of the Nile (it was moved, brick by brick, to the Met). That seems to fit just fine here in NYC, where graffiti and tagging has always found a comfort zone.Shaft Space, Space is at a premium in NYC, which is why new construction tends to make the most of its allotted square footage. When the Bowery's New Museum was built in 2007, a last-minute design change took advantage of a structural shift between the third and fourth floors to create an unexpected, oddly shaped gallery space—fitting for this asymmetrical stacked-box structure. The Shaft Space measures a mere 5 feet by 8 feet, though rises a whopping 35 feet; the museum only displays works custom built for that gallery.The Cloisters , the Met Cloisters The itself is something of a mystery, a medieval-styled Met institution that's located way uptown in tranquil Fort Tryon Park. Those who come here for the views, the cloistered gardens and the gorgeous unicorn tapestries might also take note of a singular piece, a set of 52 playing cards dating from the 15th-century Burgundian Netherlands. Rather than a game of Hearts or Go Fish, this deck looks primed for a game of Hound Tethers or Fanciful Surcoats.* Hey, different times. *Not real card games, Museum of Modern Art Modern art doesn't just mean paintings and sculpture. 's design collection is unparalleled, taking in furniture, and typography. Take its acquisition of the @ symbol, as immediately recognizable as any Picasso or Van Gogh that might hang on the walls. It's not always on display, nor are the pictograms of the original that the museum also has in its varied collection, but it's very much @ homehere., Intrepid Sea, Air & Space Museum NYC doesn't seem much of a place for camping, but leave it to an to come up with a version that puts a twist on a night at the museum. Kids (with an accompanying adult) get the chance to sleep among the aircraft displayed on the ship's hangar. That's after engaging in a evening's worth of activities: exploring the Space Shuttle Pavilion, taking a flashlight tour and generally imagining themselves as soldiers on a military exercise. Their mission is even laid out in the event's title: Operation Slumber. Out by the water in northern Long Island City is a green space you're unlikely to just stumble across, unless you happen to have just visited the nearby Noguchi Museum (or arrived at the Astoria ferry stop). As a counterpoint to the smooth stone sculptures in that formal gallery-garden, Socrates is a somewhat untamed landscape dotted with contemporary, sometimes unusual artworks: perhaps a truck functioning as pond; maybe a 3-D-printed concrete row of seats. Bring a picnic and take in the sculptures and scenic views of Roosevelt Island and Manhattan. Up in the South Bronx, this undervisited institution screens films, holds workshops and puts on exhibitions that highlight social issues, local history and journalistic efforts. There's also a photography library open to the public on Saturday afternoons; it holds much of the collection of the late photojournalist Tim Hetherington, who was killed in 2011 while covering the civil war in Libya. Though the whole place is relatively small scale, it's a key resource that many borough filmmakers and photographers lean on.The secrets of tessellation, fractals and symmetry lie behind the pi-shape door handles of this Flatiron museum. But maybe the real secret is that it's a totally fun place to learn principles of mathematics through exercises like taking a basketball free throw, pedaling a square-wheeled tricycle, piloting a car around a Möbius band and using your feet to walk a winding path without retracing any steps. On a somewhat gritty Williamsburg block, a small museum that started off as a display in Dave Herman's window serves as a welcome vestige of yesteryear's NYC. Think of the Reliquary, with its colorful, bodega-like exterior, as a microcosmic cross between a historical society, an outsider art museum and an homage to bloggers fond of old times. There's a Jackie Robinson shrine, vintage seltzer bottles, statuettes of Lady Liberty and other local memorabilia crammed into the small storefront. You'll also find hanging around a roller-disco ball (for an exhibit through November) and the original neon sign from the 2nd Ave Deli/restaurants/2nd-ave-deli which reminds us of another City secret: the sidewalk that fronts the classic's former East Village location holds the .
