Complex sentence: The project is sited above the Vanderbilt train yards belonging to the adjacent Atlantic Terminal station, formerly named Flatbush Avenue; the Atlantic Yards development was first named after this westernmost stop on the Long Island Rail Road (LIRR) 's Atlantic Branch.
Split into simpler sentences: The project is sited above the train yards belonging to the adjacent Atlantic Terminal, from which it gets its name. Formerly called Flatbush Avenue, Atlantic Terminal is the westernmost stop on the Long Island Rail Road's (LIRR) Atlantic Branch.