Some 16 miles east of Aberystwyth along the A4120 and then the B4154 you will find the Valley of Cwmystwyth, a once glacial valley now dotted with mine workings that date back to the times of ancient Britons. The Romans also worked these mines searching for lead, silver and zinc and they have been continuously mined up until the 1950's, making Cwmystwyth one of the most important historical mining areas in Wales.
The Valley is quite baron and a single lane road winds its way past the old mine workings and along side the River Ystwyth up into the Cambrian Hills. It's worth mentioning that if you have children with you, some parts of the old mine workings and buildings are dangerous. Once you have finished exploring, head up the road over the top of the Cambrian Hills for some spectacular views before heading down into Rhayader for a spot of lunch.
More information on Cwmystwyth.