ledge (n.)

late 13c., "crossbar on a door," perhaps [OED] from the Middle English verb leggen "to place, lay" (see lay (v.), and compare ledger). Others suggest a Scandinavian source cognate with Swedish lagg "the rim of a cask." Sense of "narrow shelf" is first recorded 1550s; that of "shelf-like projection of rock" is from 1550s.