Course description:  This full day course involves a minibus drive to the south western area of the National Park. The 2.7 mile (4.3km) walk crosses open moorland to reach the Hepste valley where the spectacular Sgwd yr Eira waterfall is found. This waterfall is unusual in that it is possible to walk behind it, although currently this is not possible due to safety reasons. If time permits, it is also possible to visit the huge cave mouth of Porth yr Ogof.

Main Activity: The walk starts at the village of Penderyn, the site of a working quarry. It continues across open moorland and, through activities en route, the children discover how people in the past were dependent on natural materials in their daily life.

At the waterfall itself, the children learn through demonstration, how it was formed and can walk behind the waterfall to see the evidence themselves. On the return journey, the children identify the ways in which the National Park has improved access to the area for walkers.

Porth yr Ogof: If time and the weather permit, it is also possible to visit the huge cave mouth of Porth yr Ogof, a short drive away. Through demonstration, the children learn about the properties of limestone and how the cave and other limestone features were formed. They are able to explore the mouth of the cave and search for a fossilised crab approximately 340 million years old.