Kentmere Tarn

Type; Natural, restored
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Location; Kent valley
Accessibility; Private but with footpath to west
Grid Ref; NY 455 029
Elevation; 148 m (487 feet)
Size; 900m x 150m (2925 x 470 feet)
Area; 6.0 hectares (14.85 acres)
Depth; 9m (30 feet)
Meaning of name;
Alternative name(s);


Kentmere Tarn has an interesting past. The original tarn was shallow and an ideal habitat for algae called diatoms. Gradually, as these creatures died their skeletons formed a thick deposit on the lake bed and then tar began to silt up. In the 1840s it was further drained to try and improve the grazing land around the valley. This was not successful and it reverted to a boggy marshland, overgrown with sedge and rushes.

Then, in the 1930s, it was discovered that the diatomite (silica from the diatoms' skeletons) was commercially viable for its heat-insulating properties, so operations began to extract it. Once collected, it was dried, ground and mixed with asbestos to make insulating boards and materials. Extraction ceased in 1971, it being cheaper to import the diatomite, but the result was that Kentmere Tarn had returned.

The eastern bank is inaccessible, although there is a fishing entrance near the top. However, a footpath runs along the western shore from the works entrance to the south up to Kentmere village to the north. Parking can be difficult, however, as it is a popular place. The tarn can be seen from the Kentmere road although stopping can also be tricky as the only places to pull off are designated passing places. I have managed a few pics from this side, but suspect the best views are going to be from above to the east or west.