The reflective spherical structure at the centre of this pavilion is in fact an optical device. Eleven prisms, arranged along the top of the sphere bend and break the daylight as it enters the device, casting a rainbow onto the curved inner surface of the sphere. The prisms are positioned according to the path of the sun at Al Thakhira, so that, depending on the day of the year, the weather, and the time of day, the arc of light appears in different intensities and at various places within the sphere. On a few days of the year – on the solstices and the equinoxes – the rainbow materialises, for a brief moment when the sun reaches its apex, as a perfect circle.