Caernarfon is small enough to walk in its entirety. The walled town is barely 200 metres across, and the main outlying sights — Segontium, Twthill, the bus station, the harbour — are all within ten or fifteen minutes on foot from Castle Square.
For day trips into Snowdonia and out along the Llŷn, the Sherpa'r Wyddfa bus network and the regular TrawsCymru T2 service from Caernarfon make a car unnecessary for most travellers, though a car is the most flexible option. Bikes can be hired from shops near the harbour for the Lôn Eifion and the Llŷn Coastal Path.