I'm from north Wales, I can also advise against Rhyl hehe but Anglesea is so beautiful as well as betws y coed which is my favourite place, A huge waterfall called swallow falls, loads f amazing stone cottages, lovely pubs, restaurants as well as art galleries, pottery shops and amazing rugged scenery, would be ideal for relaxing with the dog too. Conwy is gorgeous, the castle is beautiful, there's a little place called Rowen nearby which has a secret field next to the most amazing pancake house and little tearoom that also do the most amazing elderflower champagne! North Wales has lots of hidden gems, you can't go far wrong with Conwy, Betws y Coed, and Anglesea. A few nice attractions include Bodnant gardens, Porth Madog, pilli palace. Have fun! X