Wadi Bani Khalid, about 70 km north-west of Sur, is widely regarded as one of the most beautiful wadis in Oman. Unlike most wadis that dry up in the summer heat, Bani Khalid has year-round springs — deep, clear turquoise pools set in a canyon of pale limestone, fringed by date palms. You can swim in the main pools; a path leads further up the wadi to quieter spots beyond the day-tripper crowds.
The road to the wadi passes through several small mountain villages with traditional stone-and-mud architecture. The main swimming area is accessible in an ordinary car; 4WD is needed to explore further up. Bring plenty of water, shade, and food — the facilities are basic. Plan for a full day rather than a rushed half-day.