Penn(sylvania) Station, New York City, is located below ground level between West 31st and West 33rd Streets in Manhattan, with its depot facilities at or near ground level between Seventh and Eighth Avenues and platforms extending west under the Farley Post Office Building almost to Ninth Avenue. Since the 1960s, the depot facilities at ground and sub-ground level have been located beneath the Madison Square Garden arena, with an almost separate Long Island Railroad set of depot facilities to the north of the main concourse. There are connecting (at the pedestrian passenger level, below ground) subway stations on both the Seventh Avenue and Eighth Avenue sides.
The twelve island platforms (serving 24 tracks) and two stub-end west-facing platforms (serving four stub-end tracks) are used by the Long Island railroad (the two most northerly island, plus shared use of the next three), Amtrak (the third through ninth island from the north), and New Jersey Transit (the four stub-end tracks, plus availability of the more southerly island platforms when needed). There are five sets of pedestrian bridges connecting platforms in the underground space occupied by the platforms, two of which connect with "gates" in the main concourse directly above.
On the west end of the station (MP 0.0), where the tracks are open to the sky above, there are four LIRR storage tracks to the north, six tracks heading west, reducing to two as they enter the Hudson [North] River Tunnel, and additional storage tracks on the south side as well as the single track Empire Connection, with crossovers at XN (MP 0.1) and at A (MP 0.2), where the Empire Connection diverges.
On the east end of the station, the tracks head directly into two separate tunnels, once for three tracks from the Amtrak platforms, under 32nd Street, and one for three tracks from the LIRR platforms, under 33rd Street. There are crossovers at C and at JO (both at MP 0.1 in that direction), handling the tracks into the two different tunnels. The East River Tunnels turn from an east-southeasterly heading, as they exit the station which has that orientation, to almost due east as they pass beneath the East River, and then east-northeast as the tracks exit the tunnels in Queens. There are crossovers at F (MP 3.0), where the two groups of three tracks consolidate into four running tracks and two loop tracks, tracks from the LIRR Long Island City station trail in on the south side, there are bridges overhead carrying tracks into the southwest end of Sunnyside Yard, which lies along the northwest side of the line at this point, and the loop tracks diverge on the southeast side to descend and pass below the main tracks as the loop makes an anti-clockwise semi-circle to the northeast end of Sunnyside Yard.
There are additional crossovers at Harold (MP 3.7), where the LIRR tracks turn away southeast and the Amtrak tracks turn north.