A settlement developed outside the castle gates. It grew into the town of St. Clears during the 12th century. The town was never very large, but the site was important as the centre of a lordship. St Clears was later created a borough with its own charter.
The town was protected by a massive earthen bank and ditch, topped by a stout log fence. It was entered through gateways which may have been stone-built. The map shows the line of the defences, and the short stretch that still survives.
This was excavated by Dyfed Archaeological Trust in 1990. Later inhabitants settled outside the town gates. The picture shows how densely built-up the properties were. Like any other medieval town St Clears would have been crowded and bustling.
Though most people probably farmed the open fields that stretched beyond the defences, some manufacture and trade were also conducted. The map also shows the location of wharves and the town mill below the castle.