ChesLen Preserve is a 1,282-acre private nature preserve whose creation grew from philanthropist H.F. "Gerry" Lenfest's donation of 568 acres to Natural Lands, which inspired Chester County to transfer 500 additional acres and establish the preserve. The property was once part of the 17,000-acre King Ranch, where cattle were shipped from around the country and prepared for sale at market. It also includes the circa-1800 potter's field, a cemetery that remains from the Chester County Poorhouse once located nearby.