School Aycliffe is split into two by the road named School Aycliffe Lane. One side has the older, original estate. This is part of the County Durham unitary area, formally Borough of Sedgefield. The School Aycliffe Wetlands is a County Durham wildlife habitat site which is situated behind this estate. The other side is now a new housing estate named 'The Chestnuts', and part of Borough of Darlington. The now closed Aycliffe Hospital, a mental health institute, was located here.