Bir Wahed — "Well Number One" — is the classic stop on the desert safari out of Siwa. Roughly 15 km west of town, just inside the Great Sand Sea, a hot sulphurous spring bubbles up at around 40°C into a small concrete pool. A hundred metres away, a cold freshwater pond sits surrounded by reeds.
Most trips arrive in the late afternoon: hot soak, then a cold plunge, then mint tea from a sand-cooked kettle. Mornings are quieter if you want the place to yourself. Bring a swimsuit, a towel, and shoes — the spring rim gets very hot in summer.