A giant sundial divides the desert light with a tall triangular mass of cream masonry. A steep stair follows its sloping edge toward a small shaded summit. Openings in the thick wall reveal its depth, while a triangular shadow stretches across the reddish paving below.

Low curved walls frame the central structure and repeat its pale, chalky surface. The empty courtyard leaves the architecture and the changing direction of light as the main subjects. Blue sky and distant hazy hills make the observatory feel both precise and remote. Seen from an off-center ground-level position, the sundial becomes a monumental arrangement of slope, curve and shadow, with small imperfections in the stucco preserving its physical character.