'Hemels Gewelf' (celestial vault) is an art work by James Turrell in the dunes of The Hague where the presence of light can be so tangible. A artificial crater on top of one of the highest dunes allows one to look at and enjoy the sky. The elliptical, natural bowl is 30 metres wide and 40 metres long. On another dune nearby, there is another bench, with a view of a similar celestial dome, but then from horizon to horizon. The work is not a sculpture in the landscape but a tool to look at light and colour.