The shepherd walk starts in the middle of the village of Ponterwyd. Ponterwyd is a small neighbourhood situated among the mountains of Cardiganshire about 12 miles from Aberystwyth on the turnpike road leading to Llanidloes (Ponterwyd British School, 1862). The walk will take you over a stone arch bridge, built in 1780.

Further up, there is a ruin, once the home of Sir John Rhys (d. 1915), principal of Jesus College, Oxford - there is a plaque which marks this. On the walk, you will see derelict farm buildings. All these buildings used to be part of the Lovesgrove Estate.

Many of the roads are no longer accessible as they are used so infrequently. The wool packers and sheep-shearers who used to populate the area have largely disappeared.

Keep your eyes peeled for red kites as Mid Wales is now one of the bird's strongholds. There has also been an increase in foxes and badgers locally which some say has led to a decrease in ground-nesting birds in this area. The area was noted for its grouse population once upon a time, but local shepherd Erwyd Howells says he hasn't seen a black grouse since 1973.

There are a number of archaeological sites on route which include a kerb grave and a Roman rabbit grave! You will pass by another farm. Its occupant left to join a Welsh colony in Patagonia.

The rivers Hengwm, Llechwedd-mawr and Rheiddol have been dammed on Plynlimon's western side to form the desolate, black-watered reservoir of Nant-y-Moch, the final stretch of the walk. According to The Rough Guide to Wales, 'there is little sympathetic landscaping here, the lake looking nothing more than the flooded valley that it is'.

There is a great deal to be said about the history of Nantymoch - its formation in 1961 when the land was drowned (at a cost of more than £8million). The Visitor Centre at Cwm Rheidol houses various artefacts from a farm and adjoining chapel which 'disappeared' when the reservoir was created.

The ruin of Nant Llyn, a working farm, is towards the end of the walk. The walk finishes on the Cardiganshire / Montgomeryshire boundary, near the river Rheidol. There is a bridge spanning the river which was flooded in 1973.

This walk was written by presenter Jon Gower for the BBC Wales series 'Homeland'.