Wikipedia
Colsterdale
Colsterdale is the valley of the River Burn, a tributary of the River Ure, in the Yorkshire Dales in North Yorkshire, England. It gives its name to a hamlet and civil parish in the upper part of the dale, about miles west of Masham. The population of the civil parish was estimated at 20 in 2010. The lower part of the dale is in the civil parish of Healey. The area is in Harrogate district. Although Colsterdale is not in Nidderdale, it lies within the Nidderdale Area of Outstanding Natural Beauty.
The Colsterdale towers are towers built between 1895 and 1911 to conduct surveys.