In continuing my search for reference material, I went on the cave tour at Nottingham Castle, which consists of an underground passage leading from the castle to the street below. It was interesting to learn that all of the caves within Nottingham are man-made. I didn't consider this before, but it is due to the local sandstone, which is easy enough to carve into, but holds its shape enough to be able to form safe passageways.
These particular tunnels were made to be able to transport goods from what would have been the canal below, and there are hand carved steps and niches where they would have placed lanterns and stored projectiles to defend the castle.
I was inspired by the way in which the sandstone had worn with age, and of how it had weathered and discoloured from the effects of acid rain. There were also different coloured layers in the rock that were interesting. When I get time, I will see if I can collect some of the dust from the base of the Castle Rock and create a pigment similar to the Hemlock Stone pigment I made before.
