The underside of the arch divided in half diagonally and coloured with oxide powder.

"The arches suggest the impulse to establish a relationship with one's environment, to articulate a response to the world outside ourselves. It is reminiscent of cathedrals which, in more complex fashion, represent the heavens in their vaults and domes. The curved form of the arch also articulates a response appropriate to an open-air location - it provides a protective cover at the same time as recognising the openness of the earth to the elements of sky, rain and wind, while also marking human activity within it. To turn an arch into a pastel drawing seemed to be one way of continuing this perennial human activity of acknowledging the space outside ourselves, as well as an expression of spontaneity and altered scale, which the site also suggested. "