A big, rather untidy plant grows in the brambles and bushes on the side of a path. It has a lot of blue flowers.
Nettle-leaved bellflower (Campanula trachelium) produces all summer, and even after it, blue or lilac bell-shaped flowers on long sturdy stalks. It does not like full sunshine so you will find it mostly in the shadow of trees, sometimes together with the Clustered bellflower that now already has stopped flowering.
The flowers are hairy, even inside!
The triangular leaves (yes, like nettle leaves) are also hairy. Here those of a small plant just before it started flowering.