Pilgrim Psychiatric Center (abandoned buildings)

Opened in 1931 in Brentwood, Pilgrim was the largest psychiatric hospital ever built, peaking near 14,000 patients. The campus today is a patchwork: an active state hospital, land ceded to Suffolk County Community College and Brentwood State Park, waves of demolition (2003, 2011-2012), and a rump of derelict ward buildings — most famously Building 82 — that still rot behind the active facility. The grounds are patrolled and trespass arrests are common; interiors feature collapsed floors, asbestos, and elevator shafts. One of Long Island's most tempting and most enforced sites.