We were, let me explain, sitting under a horse chestnut tree and at this time of year trees like this drop their nuts (“conkers”). Horse chestnuts are similar to the sweet chestnuts which are being roasted on our streets at this time of year, but they are not good for eating (not for us humans, at least). But when they fall from the tree they lose their green husks and reveal their beautiful shiny, slightly marbled, chestnut brown skins.