This plant with its small round leaves contrasts nicely with recently fallen Sweet Chestnut leaves. It is Wild basil (Clinopodium vulgare) at the end of its flowering season.
There are not many flowers left and it looks like they are all sitting on their own, not grouped together. For that reason they could be confused with Calamints (the other plants of the genus Clinopodium). Use your nose: most Calamints are perfumed, a smell somewhere in between mint and marjoram, more or less strong. Wild Basil has no particular smell, it smells green, that's all. And its name? Should be the shape of the leaves, not the smell.
Normally many flowers are grouped around the nodes, forming little round structures.
In autumn the plant has no strength left to make more than a few flowers.
Dried-out calyxes that had flowers a few weeks ago are all what is left.
You can find them everywhere, Wild basil is a common plant on many kinds of soil. But it seems they have a preference for sides of a path. To the delight of walkers.