Port Eynon is the most southerly point on Gower and is thought to be named after an Eleventh Century Welsh Prince, Eynon. It is believed that he built Port Eynon castle which has disappeared over the years. Once there was a booming trade in Oyster fishing (the remains of the Oyster Pools and the old harbour wall can be seen at low tide), limestone quarrying, lobstering and crabbing, but as with many little ports also came reports of smuggling. At one stage, it is thought that eight excise men were stationed in the village alone.
At the far end of Port Eynon Bay stands the Eighteenth Century ruin of the old Salt House. Originally extracting salt from the sea, (the sea in Port Eynon has an especially high salinity) it is thought that the business was run as a cover for smuggled goods. Maybe this theory is not too far fetched when you consider that most of the local population of the 16th, 17th and 18th centuries appeared to have been involved in smuggling. On one notable occasion, the goods were hidden in the church!
Extracted from the village website