West of Penrhyn Du is Porth Ceiriad, so named after Caer Pared Mawr Fort which is in the distance of the photograph below. It was an Iron Age fort with extensive defenses even though it enclosed only one sizable hut housing one large family and their animals.
It is hard to imagine now but had you stood on these cliffs around 8000 BC and looked across where Cardigan Bay is today you would have seen nothing but plains and forests. This is before sea levels rose to what they are today. Fossilized tree stumps found in the bay from this period could be the source of the Welsh legends of the lost lands of Cantre’r Gwaelod (the Lowland Hundred), a legendary sunken kingdom. It is said that the sunken church bells of this kingdom ring out in times of storms and danger.