DR. GERHARD BERSU'S EXCAVATIONS IN CWM YSTRADLLYX By C. A. Gresham. B.A. D.LITT., F.S.A. EXCAVATIONS in a group of circular stone-built huts on the slopes of Braich-y- cornel in Cwm Ystradllyn, Caernarvonshire, were carried out bv the late Dr. Gerhard Bersu during two seasons' work in March, 1950, and October, 1953. Dr. Bersu was not able to complete the work, and he died in 1962 without having produced a report. His notes, plans and photographs were kindly handed over bv his widow to Mr. W. E. Griffiths of the staff of the Royal Commission on Ancient Monuments in Wales and Monmouthshire. Dr. Bersu had asked the present writer to add to the final report, when it should appear, a section dealing in general with the numerous hut-sites in the Cwm Ystradllyn district, which were then unpublished, and as the surviving notes do not provide sufficient material on which to base a full excavation report, Mr. Griffiths has allowed me to make use of them in this paper by combining what has been preserved with my own observations. In 1938 and 1939, I made a detailed survey of the hut-sites in the region of south-cast Caernarvonshire which is taken up by the two large ecclesiastical parishes of Penmorfa and Llanfihangcl y Pennant. I there recorded some sixty sites con- sisting of what I termed Single Huts, Unenclosed Groups and Enclosed Homesteads. When members of the staff of the Royal Commission came to survey the same district some twelve years later, they were able to add only two or three odd huts to the sites I had previously found and recorded on six-inch maps, so it can be assumed that field-work there is reasonably complete. The Commission gives full details of these sites in its Inventory for Caernarvonshire Central. Volume II. where they will be found mainly in the civil parish ofDolbcnmacn. It was clear from the preliminary survey that the concentration of hut-sites in the Cwm Ystradllyn district was quite remarkable, but at that time not very much was known about the distribution pattern of these sites in the rest of Caernarvonshire and in Merioneth, except that the researches of Elias Owen and Bezant Lowe had shown that huts were numerous in Arllechwedd Uchaf along the north coast of Caernarvonshire. So, although there was much material in hand, the time was not ripe for detailed publication; however, at the request of the editor of the Transactions of the Caernarvonshire Historical Society, I published a summary of what was then known about the sites in the county.1 Extended research over other parts of Caernarvonshire and Merioneth soon revealed that as well as the three types of hut-site already mentioned there was a fourth to which the name Concentric Circles was given. The names suggested have by now been fairly generally accepted as a working basis for the sites in north W ales extending west from the river Conway all round the seaward-facing slopes of the mountains as far south as the river Dyfi. After the war was over in 1945 the time had come to attempt to date the various types of hut-site by excavation, and the Caernarvonshire Excavation Committee was Transactions of the Caernarvonshire Historical Society. Vol. 3. 1941. 1 8.