Two different types of medieval bole furnaces were constructed on the exposed valley-side plateau at Pengeulan; a pit bole hearth and an elevated vole hearth. Excavated in 2002 and published as Timberlake, S. 'Medieval Lead-smelting boles near Penguelan, Cwmystwyth, Ceredigion', Archaeology in Wales 42, 45-59.

The Banc Tynddol Bronze Age 'sun disc' (NPRN 412409) was found during these excavations.

T. Driver, RCAHMW, 4th Jan 2011.