Though the grain and later sawmill established by William Penn and his partners are long gone, the low, rubble stone-walled house of partner and manager Caleb Pusey on Chester Creek still stands. Pusey's importance as county sheriff and, later, surveyor of the area that forms the border between Pennsylvania and Delaware is belied by the rude nature of his house. The east section of the house dates from 1683, but its gambrel roof was added in the mid-eighteenth century; the western section is also pre-1700 and may been an unroofed animal pen before being roofed over. Framing methods within recall late medieval European practices. This is probably the only house standing in the commonwealth that can be proven to have been visited by William Penn. It affords evidence of the expedient architectural forms in the first settlement zone and compares with the slightly earlier John Boelsen cottage (c. 1680) on W. River Drive in Philadelphia's Fairmount Park. The Pusey house is operated as a museum.