The Hafod Estate in the Afon Ystwyth river catchment is a landscape that was formed by a combination of ice and water. During the peak of the last ice age, 25,000 to 20,000 years ago, this area would have been covered by a thick blanket of ice. Glaciers, rivers of ice, would have flowed from the uplands towards Cardigan Bay, widening and deepening the valleys. Most of the ice disappeared roughly 15,000 years ago, but its impact on the environment can still be seen. Today, the Afon Ystwyth flows through one of these valleys.
At the Hafod Estate, several smaller streams flow from the uplands into the deep Ystwyth valley, forming spectacular waterfalls on the valley sides before joining the river. Examples include Nant Peiran, Nant Gau, and Nant Bwllchgwallter. In the past, people have tried to improve the appeal of the landscapes around these waterfalls. Others have tried to improve access to spectacular viewpoints, for example at the Grotto (currently closed) on the Gentlemen’s Walk.
The spectacular Ystwyth Gorge is evidence of continued river erosion into the surrounding bedrock happening over tens of thousands of years. Ystwyth Gorge’s deep and narrow channel has excellent examples of river potholes. River potholes are circular to oval shaped depressions in the rock that are formed slowly over time by the swirling of sediment in fast flowing eddies. The Afon Ystwyth at Hafod also has great examples of gravel-bed river forms such as pools, riffles, gravel bars, and meanders.