As part of a wider exercise to survey all of the caves around the Ystradfellte area, Eric and I have produced a survey of Ogof Coeden Prop and Ogof Ganol (see next page). We are now in the process of surveying Ogof Ffynnon. Eventually, we intend to publish a complete survey of all of the caves, including their positions in relation to each other and the surface.
A description of Ogof Coeden Prop can be found as reference 15 in the 'Caves of the Mellte Valley' by Allan Ockenden. The cave was surveyed because it lies on the projected line of the lower cave in Ogof Ffynnon and it was hoped that it would provide a better means of entry to this cave. However, the lowest levels of Ogof Coeden Prop do not provide a particularly suitable site. The shakehole takes a stream which does not appear to flow directly into the cave, and may even provide a last resort dig site if Ogof Ffynnon does not yield.
The other cave shown, found between Ogof Coeden Prop and Ogof Ffynnon, also lies on this projected line. However, apart from freezing one's bollocks in the water found in the small chamber, Ogof Ganol has nothing to offer.