Maen Llia stands near the Roman Road, Sarn Helen, where it crosses the mountains between Fan Nedd and Fan Llia.
Cwm Rhondda
Both Rhondda Fach and Rhondda Fawr descend from the nameless mountain which rises steeply above Tower Colliery. The two valleys meet near St. Mary's Well, a hidden, neglected and ancient shrine, still venerated by a few catholics, from where the valley winds down to Pontypridd where it joins Cwm Tâf.
Cwm Cynon
Afon Cynon finds its main water supply from a series of springs at Penderyn and from Cwm Cadlan which flows down to Penderyn from the East. Because the substrate here is deeply fissured limestone, much of the flow is underground, and the riverbed is frequently dry in Penderyn in summer.
Hirwaun can be considered as the Heart of the Heads of the Valleys, and is famous as the origin of the red flag of socialism, which was first raised on Hirwaun Common, which is on the nameless mountain above Tower Colliery, which has itself more recently become famous as the only coal mine to be bought up and rescued from closure by its own miners.
The river Cynon flows down from Hirwaun through Aberdare (Aberdâr) and Mountain Ash (Aberpennar), to join the Tâf at Abercynon.
The centre of Hirwaun is the Cardiff Arms, which has a dance floor and I used to like when I lived in Penderyn. The disco at the Bod (Bodwigiad Arms) has started again. For a traditional village pub with no music (except when the inmates burst into song), try The Lamb in Penderyn. For courting couples and others who wish to be left to themselves, Llew Goch (The Red Lion), on the hill by Penderyn church, is recommended, but if you leave late, look out for the ghost which haunts that neighbourhood.