Llyn Llydaw: an imprisoned lake

Abstract

One of the greatest scientific discoveries of the first half of the 19th century was that the Earth had undergone an Ice Age. Many of the earliest confirmations of this fact were made in the Alpine valleys of Switzerland, but it did not take long for British geologists to scour the highland areas of Wales for similar evidence. One such scientist was A. C. Ramsay, and his investigations took him to Llyn Llydaw in Snowdonia: ‘Approaching Llyn Llydaw, the full grandeur of this wonderful valley bursts on the beholder. A lake rather more than a mile in length and of a green colour, like some of the lakes of Switzerland, obliquely crosses the valley.