Dealey Plaza's grassy knoll and abrupt local rise

Dealey Plaza in downtown Dallas contains a small but distinct raised embankment-commonly called the grassy knoll-immediately adjacent to Elm Street and the nearby railroad underpass. This abrupt local rise and the plaza's sloping terrain form a notable topographic irregularity in an otherwise relatively flat downtown area. The knoll and plaza are preserved as part of Dealey Plaza National Historic Landmark District.