The Piers

From NYC LGBT Historic Sites Project: 

By the early 20th century, Greenwich Village's Hudson River waterfront and numerous piers with Beaux Arts style shipping terminals comprised the busiest section of New York's port for cargo and trans-Atlantic passengers, with merchant ships, steamships, barges, and commuter ferries.

Changes in the maritime industry and the growth of the airlines made the piers and the large shipping terminals obsolete, leading them to be abandoned by the mid-1960s. The dilapidated structures - including Pier 45 (known as the Christopher Street Pier) opposite West 10th Street, and piers 46, 48, and 51 - were reappropriated as a destination for gay men to sunbathe naked, cruise, and have public sex by the early 1970s.