Welsh Journals

OGOF-YR-ESGYRN, DAN-YR-OGOF CAVES, BRECKNOCK EXCAVATIONS, 1938-50 BY EDMUND J. MASON LOCATION THE site to be described is at Glyntawe, in the Swansea Valley, Brecknock (National Grid Reference SN 83781604). The River Llynfell is a small tributary of the Tawe and joins the latter within a short distance of emerging from the river cave of Dan-yr-ogof on the western side of the valley, close to Dan-yr-ogof Farm and about 730 yds. north of Craig-y-nos Castle. About 140 ft. above the mouth of the river cave are three small caves of which the largest was known prior to 1938 as Yr-ogof-ganol and sometimes as Yr-ogof, as described in the report by D'Elboux (as note 1). As this name was often used for the river cave it was decided, at the request of the owners after discovery of bones in 1938, to change the name Yr-ogof-ganol to Ogof-yr-esgyrn The name Dan-yr-ogof caves now indicated not only the river and commercialized parts of the cave system, but also Ogof-yr-esgyrn and other caves in the same complex. DESCRIPTION OF THE CAVE AND DEPOSITS The cave consists of a single chamber, roughly rectangular in shape, having a width of 66 ft. east to west and a depth north to south of 36 ft., entered by a north to south passage 22 ft. long and 8 ft. to 15 ft. wide where it joins the north-east corner of the chamber (Plan, Fig. 1). Although the height of the chamber generally varies between 9 ft. and 11 ft. the greater part of the entrance passage is little more than 4 ft. high. The gross superficial area of the chamber is 230 sq. yds., but only about 60 sq. yds. contained deposits which could be excavated, the remainder consisting of stalagmite exposed or slightly covered, or destroyed by stream action. These areas, which it was possible to excavate, consisted of red brown earth, inclined to be humic in character, particularly nearer the entrance, and distinctly muddy where subjected to roof dripping. It was friable enough to be sieved after exposure to the open-air. The soil, which varied from an inch or so to about 2 ft. in deeper pockets, rested directly on a stalagmite floor or on limestone boulders.