Interesting Wall Stone

Mr Flum's Father was born in Sunderland, a town we have never visited, so we took a diversion on the way home to see it, or at least the river.

Then we noticed the National Glass Centre and went in (well worth a visit, do look at the link) and watched glass-blowing, bought a piece used in a demonstration and had a nice lunch.

Near to the centre is St Peter's church, built in Saxon times, and the wall between is composed of a remarkable variety of stones, including many with obvious indications of their limestone origin, like this, which reminds me of a fan coral. (For scale, there is a little plant down in the bottom left corner).