Located on Anglesey island off the north-west coat of Wales, Aberffraw, e.g. Treath Mawr (which means Big Beach) is known for being one of the most dog-friendly beaches in the UK. It's also ideal for long, scenic walks. Backed by extensive low sand dunes, the beach feels like it stretches for miles and miles, and you have access to the Anglesey Coast Path, which runs from the beach in both directions.