Opposition is growing against plans to turn a nature reserve in Cornwall into a china clay waste tip.
Hendra: Imerys says the reserve will close in the autumn
Hendra pit at Nanpean, near Saint Austell, was dug for china clay mining.
But when reserves were depleted five years ago, owners Imerys opened it to the public.
Now the company wants it back, to use as a china clay waste tip.
Wildlife at the reserve includes foxes, buzzards, owls and rare plants like orchids.
English Nature is backing opponents who held a public meeting in Nanpean on Tuesday.
Local resident Chris Davies, said: "I am horrified because it gives me somewhere I can take the dogs for a walk, let them run free.
Imerys is emphasising its environmental work
"My kids come over here, pick blackberries in the autumn. It's a great place to be."
Imerys says tipping at Hendra will close in the autumn.
The firm said it always made it clear it may need to re-use the pit, because it did not want to create new waste tips.
Spokesman Ivor Bowditch said: "We understand people's concern and we shall be offering an alternative site, or sites.
"This pit has planning permission and we are desperately short of ground to tip."
The public meeting follows the announcement by Imerys last week that it was committing itself to the county for at least 40 years.
Environmental action was an important part of the plan.
Imerys said it would be stemming pipeline leaks which have led to repeated prosecutions, filling in tips with waste rather than creating new dumps, and planting new heathland and woodland.