In the 13th century a defensive wall was erected around Trim to defend the town and the castle. Access to the town was granted through five gates. Though not much remains of the original walls of Trim, the "Sheep Gate" stands near the 'yellow steeple' and the castle. The wall in this area is in ruins but it marks the original town boundary, the only intact part of the wall stands on Loman Street It is not marked by any signs but it starts around the front of St. Patrick's Anglican Cathedral and runs down to The Priory Pub.
The other gates were Athboy Gate to the north, Water Gate to the west, Dublin Gate to the south and Navan Gate to the east.