17.3km/10.7 miles/6 hours
Ascent 772m/2533ft
Andrew Galloway visits a secluded valley where disaster once struck
WITH AN ABOVE-AVERAGE annual rainfall, the valleys of Eryri/Snowdonia were an attractive proposition for the burgeoning hydroelectric and aluminium smelting industries of the early 20th Century. In 1907 the Aluminium Corporation Limited (ACL) set up shop in the Conwy Valley close to Dolgarrog, constructing a concrete dam almost 1km in length along the eastern shore of