The waterfilled disused quarry at Foggintor.
An email from Mr. D. Thorne has this comment:
In the mid 50s these waters were filled with brown trout which had been placed there from local rivers. I Fished there until the 80s when the trout seemed to vanish. The strange thing was that although they were trout from the locale, because of some chemical or other in the water they were bluish in colour.