400km (249 miles) W of London; 100km (68 miles) W of Chester; 48km (30 miles) SE of Holyhead; 14km (9 miles) SW of Bangor
In the 13th century, when King Edward I of England had defeated the Welsh after long and bitter fighting, he felt the need for a castle in this area as part of his network of fortresses in the still-rebellious country. He ordered the construction of one on the site of an old Norman castle at the western end of the Menai Strait, where the River Seiont flows into the sea, a place from which his sentinels could command a view of the land around, all the way to the mountains and far out across the bay to the Irish Sea. Based either on his firsthand observations (historians believed he might have visited Constantinople during his involvement in the Crusades) or on ancient drawings of Constantinople procured by his architect, the Savoy-born James St. George, the walls were patterned after the fortifications surrounding ancient Byzantium. Most of the walls of the 13th-century town still stand, although growth outside the walls has been inevitable.
The main reason to come here today is to see the castle. After that, you will have seen the best of Caernarfon and can press on to another town for the night, or else stay at one of the local inns. The downside? Tourist buses overrun the place in summer. Other than the castle, there is nothing in the town that needs to take up too much of your time.