Beaumaris (Biwmares) in detail
Buses stop on Church St. Routes include the 53, 57 and 58 to Menai Bridge (18 minutes) and Bangor (35 to 45 minutes); some 57 and 58 buses continue on to Penmon (10 minutes).
There's a large pay-and-display car park on the waterfront by the castle. If you're prepared to walk, there are often free parking spots on the Menai Bridge approach to town.