Sarn Gynfelyn

Sarn Gynfelyn is a stone and shingle causeway that extends roughly 14 kilometers from the cliffs near Wallog farm into Cardigan Bay. The formation features a channel about 5 meters deep at its center and becomes completely submerged during high tide.

Scientific research shows this causeway formed during the last glaciation period as a moraine made of boulders, cobbles, and different sediment layers. This natural deposit has shaped the coastal landscape for thousands of years.

Local Welsh tradition links this causeway to the lost kingdom of Cantre'r Gwaelod, with people viewing it as an entrance to an ancient realm. Today, visitors can sense the deep connection this place holds for communities in the region.

Check tide schedules before exploring, as the causeway becomes fully submerged at high tide and access is limited. Walking conditions are slippery when exposed, so plan your visit carefully around the water cycle.

The area preserves tree stumps from an ancient forest, including oak, pine, birch, willow, and hazel from around 5,000 years ago. These fossil remains offer a rare window into the earlier plant life that once covered this coastal zone.

GPS coordinates: 52.45160,-4.08190

Latest update: December 13, 2025 11:40