A favourite Siwa excursion is the freshwater lake at Bir Wahed, 15km away on the edge of the Great Sand Sea. Once over the top of a dune, you come to a hot spring, the size of a large jacuzzi, where sulphurous water bubbles in a pool and runs off to irrigate a garden.
Cooling down in the lake, then watching the sun setting over the dunes while soaking in a hot spring, is a surreal experience.