One of the delights of living here is the way in which plants grow out of the limestone walls.
The main one here is a Fern called Intermediate Polypody (Polypodium interjectum).
But you can also see at the bottom left and the top some Maidenhair Spleenwort ( Asplenium trichomanes).
And if you have the patience and a magnifying glass you would find mosses and other things,
A veritable garden on its own.