Custom House District is a historic district in Boston, Massachusetts, located between the Fitzgerald Expressway (now Purchase St. / the Rose Fitzgerald Kennedy Greenway) and Kilby Street and South Market and High and Batterymarch Streets. Named after the 1849 Boston Custom House located on State Street, the historic district contains about seventy buildings on nearly sixteen acres in Downtown Boston, consisting of 19th-century mercantile buildings along with many early 20th-century skyscrapers, including the 1915 Custom House Tower.