Ah yes I have some fond memories of lighting fires on the beach! One of the last things me and my mates did before we finished our final year was to have a great big fire and BBQ on the beach at Clarach. I built the fire and it turned out pretty nice! Here’s a piccy: http://www.therianslair.org/private/clarachfire.jpg. Highly recommended to go over there in the summer because the beach is much quieter than the Aber sea front. Plus there are great views from Constitution Hill. That said you’ll want to avoid the main tourist season because there is a big caravan park.