From “The Ancient Stones of Wales” – Chris Barber and John Godfrey Williams (1989 Blorenge Books):
“Maen Cilau is a massive monolith over 9 feet high just within the entrance gate to Abermorlais [sic] Park. It is also known as Carreg Fawr standing stone”.
According to Coflein the stone is not thought to be in its original position.