Aim to draw without sight today, I've been testing the style and site over the past week now.
See how I go.
The surfaces are concealed already by the paper, drawing what I feel, like an inverted drawn form of Braille.
Above, air raid shelter south-side. In shadow. Sandy surface residue.
Above, air raid shelter north-side. In sun.
Above, air raid shelter north-side has the original concrete entrance, the lovely rust coloured surface shown makes me suspect water damage.