Abercastle is a small harbour on Pembrokeshire's north coast. A small (free) parking area overlooks the beach and access to the shore is down a short slipway. There is a charge for launching - in 2014 it's £5 for small boats and £1 for canoes. Other facilities include toilets and a picnic table. The village of Trefin is a short walk away, and has a cafe and a pub.
The beach consists of seaweed strewn sand, with the headland on the west side becoming an island on the high tide. A cave runs through this.
It is very sheltered and is popular with anglers, canoeists and divers. The fragmented wreck of the Leysian is situated just outside the bay at about 15m depth.