Derndingle was a hollow in the south of Fangorn Forest, used by the Ents from time immemorial as the place where they met in Entmoot. In shape it was a wide round depression, surrounded by a dark green hedge of evergreen trees. The hollow itself was clear of trees, except for three tall silver birches that grew in its centre.
A dingle is a 'tree-shadowed dell'. The archaic element dern (also seen in Dernhelm) means 'secret, hidden'