Watsessing Park is a sixty-nine-acre county park in Essex County, New Jersey, extending across East Orange and Bloomfield Township near the meeting of the Second River and Toney's Brook. Designed in 1899 by the Olmsted Brothers, sons of Frederick Law Olmsted, it belongs to the late nineteenth-century tradition of parks shaped around natural waterways and open green space. Its name preserves an older Lenni Lenape presence in the area and is generally understood to mean "crooked" or "elbow," possibly referring to the sharply bending Third River elsewhere in Bloomfield. The park remains significant as both an Olmsted-era landscape and a natural stream junction in a heavily developed region.