The Dismal Swamp is a nearly 650-acre marshy wetland in central New Jersey along the borders of Edison, South Plainfield, and Metuchen, preserving a substantial natural area within an urban setting. Its red-brown shale lies in the Passaic Formation, and prehistoric stone tools show human presence reaching far back in time. Known to the Lenape as Maniquescake, the area later saw a vineyard in the 1700s, agricultural development in the 1800s, and the nearby early 1900s Russian exile settlement of New Petrograd. Today it supports about 165 bird species, including the endangered loggerhead shrike, with public access through the Middlesex Greenway and conservation activity centered at Triple C Ranch.