I have concentrated on the main wall facing the viewer, blocking in individual sandstone blocks with slight variations in colour,
overlaying with a reddish wash. At this stage I have not applied any shadow, which will help to define shapes, and give depth of
field. One thing about watercolours is that unlike oils, you cannot overpaint an area to rectify a mistake, so you must see in your
minds eye the end result before you start, and plan ahead. The finished painting must preserve luminosity, with the white of the paper
reflecting light through the washes. Overpainting makes the result "muddy" and then you realise you have overworked and lost it....