Photograph by the author.

Here is the magnificent ‘High Force Waterfall’ in Teesdale, northern England.

The term ‘force’ is from the Nordic word for waterfall: ‘foss’ — this, as well as other locally used terms, such as ‘dale’, ‘beck’ and ‘fell’, are testimony to the ancient Viking settlers who once roamed these lands.

The waterfall has two distinct layers of rock. The upper one, called the ‘Whin Sill’, is relatively newer and is igneous in origin. The lower, more ancient layer, formed…