Trooping Funnel

I thought I'd better blip the Trooping Funnel (Clitocybe geotropa) before the frost turns them to mush. This is a magnificent fungi, very sturdy with a large cream coloured cap that forms a distinct funnel shape as it ages. They are the largest fungi I've come across, standing 10-15cm high and with caps of 15-20cm in diameter. When they first emerge they have a broad umbo (there's that word again) which, I suppose, gives rise to their other colloquial name of the Monk's Head. They often form arcs or rings and the largest known fairy ring - 600 meter diameter and over 700 years old - is composed of Trooping Funnel. Apparently its somewhere in France - anyone know exactly where?