Porth  Porth () is a town and a community in the county borough of Rhondda Cynon Taf, within the historic county boundaries of Glamorgan, Wales, lying in the Rhondda Valley and is regarded as the gateway to the Rhondda Fawr and Rhondda Fach valleys because both valleys meet at Porth. The Welsh word "porth" means "gate". Porth is a predominantly English-speaking community. Neighbouring villages include Trealaw, Trebanog, Trehafod and Ynyshir. During prehistoric times the area now known as Porth was an uninhabited wooded area. Although there is evidence of settlements in the upper reaches of the valley, only cairns used as way-markers have been discovered on the higher points in the Porth area. During the medieval period the area came under the commote of Glynrhondda within the cantref of Penychen, though the area remained uninhabited. Although there were no permanent buildings of note at this time, it is known that the area would have experienced travelers with two bridges built over the River Rhondda at Porth, the Pont Rheola and Pont y Cymmer. Both bridges date to at least the 1530s when they were mentioned by antiquary John Leland. These bridges were wooden in construct and were later rebuilt in stone. The first buildings of note in the region were built to the south of Porth in the community known today as Cymmer, mainly a chapel, Capel y Cymmer (1743) and a mill on the south bank of the River Rhondda. By the 18th century there were a handful of farm houses, mainly in the northern slopes of Llwyncelyn. During this pre-industrial era, the locale was known as Cymmer, an old Welsh word that describes the point where two rivers converge. It was only during the industrial period that the mining operations of the Porth Estate and the subsequently named railway station that saw the name Porth adopted. In 1809, Walter Coffin sunk the first coal pit in the Rhondda, further up the valley in Dinas, but a lack of a transportation network greatly affected the profitability of coal mining as an industry in the region. Coffin tackled this problem by constructing a one-mile tramline which connected his mines in Dinas to a tramline built by Dr. Richard Griffiths at Denia (Pontypridd), which linked to a private canal that joined onto the Glamorganshire Canal at Treforest.