The site of Upper Mill, Brynmill (and in some records appearing as 'Bryn Mill'), now lies in Singleton Park close to its boundary with Brynmill Lane, a short distance to the north of Lower Mill. The mill first appears in financial records of the fourteenth century and was still in use in the nineteenth century. The mill went out of use and was eventually destroyed but the water course which powered it still flows through the Park. The mill pond was converted to a reservoir, still in use.
During the Middle Ages the mill lay within a milling complex in this part of the borough of Swansea (NPRN 410018).
Although the mill has been demolished traces of walling survive, abutting the Park boundary at SS63379248 amongst dense overgrowth, where one of the buildings projected into Brynmill Lane (first ed. 25-inch map). A short distance south of this is the partial outline of a rectangular stone building at SS63399244. Cleared by the park authorities, though now densely overgrown with bramble, the walling projects above a stony mound, probably part of the demolition rubble.
A broken millstone lies flat on the base of this building.

David Leighton, RCAHMW, 20 December 2010