Don’t overlook Caernarfon’s medieval town walls. Visitors flock here, of course, to see the world-famous fortress. But Caernarfon’s story is not complete without including a chapter on its ring of ancient walls. They were an essential part of King Edward I’s masterplan to create a complete fortress town settled by incomers.
The circuit of walls, studded with eight towers and two gateways, survives almost complete. Extending for almost half-a-mile, the walls threw a security blanket around Edward’s new town. The East Gate was the main landward entrance to the medieval borough. This is matched, at the opposite end of the High Street, by the West (or Water) Gate, which could only be approached from the sea in the 13th century. Some of the best-preserved sections of wall can be seen just north of the East Gate, though to get a sense of the original atmosphere of the town take a walk on the quay or along the shady Hole in the Wall Street.
https://cadw.gov.wales/visit/places-to-visit/caernarfon-town-walls