Mynydd Myddfai

The plateau surface of the hill rises to a height of 440m at OS grid ref SN 806297 where a trig point has been erected.

[1] The hill is composed of a variety of different rock formations all tilted steeply to the southeast in a structure known as the Myddfai Steep Belt.

Immediately southeast of these beds is the narrow band of the Tilestones Formation along which are a line of grassed over diggings left after these flaggy micaceous sandstones were extracted for use as roof tiles.

These last two formations are considered to be the lowermost of the Old Red Sandstone sequence though assigned like the rest of the rocks forming Mynydd Myddfai to the Silurian period.

A number of new archaeological finds in 2007/08 were made during the excavation of a deep trench across the northern end of Mynydd Myddfai for the laying of a controversial gas pipeline from Milford Haven to Tirley in Gloucestershire.