Along the north shore of the Claerwen Reservoir (west of Rhayader).
There are several traffic-free routes in the area. The easiest options are there-and-back routes but if you are fit and have a good map you can easily work out a circular route.
Distance - The trail follows the north shoreline of the Claerwen Reservoir for 6 miles (ie 12 miles return)
Start & Parking - There is car parking space at the dam at the eastern end of Claerwen Reservoir, 10 miles to the south-west of Rhayader. Alternatively you may wish to start from the Elan Valley Visitor Centre. The minor, dead-end road between the Visitor Centre and Claerwen carries very little traffic.
Surface & Hills - Stone surface (like a forest road). Several steady climbs and descents.
Ordnance Survey Landranger Map - 147