Penrhos is a small community situated between Pwllheli and Llanbedrog, just off the A499. Penrhos is home to the Pen-y-Berth caravan park, built on the former RAF base on slightly elevated land with good views over Cardigan Bay to the mountains of Snowdonia and mid Wales, the base has a long history, evidence of a small part of which can be seen in a slate plaque on the wall at the turning for the caravan park off the road leading to the small Polish community that still remain in the area from the Second World War.

Nearby, the beach at Carreg-y-Defaid is the western limit of South Beach, Pwllheli and is a popular spot with fishermen.

The Afon Penrhos would at one time have flowed into the sea here, and there are shoals in the bay from that time. The embankment which supported the Pwllheli-Llanbedrog tramway diverted the river into its current route into Pwllheli Marina.