Unity Temple represents the high point of Frank Lloyd Wright's 'Prairie' period. Still in immaculate condition today, Unity Temple is ordered on a rigorous system of proportion, determined on both exterior and interior by the measurements of the central interior sanctuary space. On the outside this concrete building is rendered as a cubic mass of stone grey; inside, Wright constructed the opposite: a space defined by concrete rendered as floating coloured planes, painted in quiet, muted colours. The complexity of geometries and interlocking spaces and forms at Unity Temple is outstanding, and invites the viewer to see the act of building as sacred, and to experience the building as a sacred place.