Does anyone, in Ontario, know where the largest concretion is located?

Question

A concretion is a circular rock formation that looks like a huge bowling ball. Smaller ones are at Kettle Rock but a friend told me of LARGE ones that used to be in that area. We went looking for them and they seem to have been removed. We have a bet on that they aren't as large as he remembers. Help me locate one..please.

Answer 1

Try over by the Sydenham River