40°44′59″N 73°55′37.37″W / 40.74972°N 73.9270472°W
Sunnyside Yard is a large coach yard, a railroad yard for passenger cars in the Sunnyside neighborhood of Queens in New York City. The yard is owned by Amtrak and is also used by New Jersey Transit. The Pennsylvania Railroad (PRR) completed construction of the yard in 1910; it was originally the largest coach yard in the world, occupying 192 acres (0.78 km2).
Harold Interlocking, the United States' busiest rail junction, is part of the yard. The shared tracks of the Long Island Rail Road (LIRR) Main Line and Amtrak's Northeast Corridor pass along the southern edge of the yard. Northeast of the yard a balloon track (or reverse loop) is used for "U-turning" Amtrak and NJ Transit trains which terminate at Penn Station. Leading eastward near the south side of the yard, this balloon track switches off and turns left under the LIRR/Amtrak tracks, turns left once again, and merges with the Sunnyside yard track to turn the train west toward Penn Station.