Thirteen-foot-tall mahogany doors with a knocker that could summon the dead. A ceiling fresco depicting the rape of Ganymede. Plaster walls chipped and mottled with age, massive columns supporting limestone lions, crystal chandeliers casting spidery shadowsâ€¦. Medieval castle? Ancestral manor house? Try a two-story loft in the heart of New Yorkâ€™s ultratrendy Chelsea district.