Two days from Muscat: Ibra, the pools of Wadi Bani Khalid, a night at a camp in the Wahiba Sands, then back along the coast by Wadi Shab, the Bimah Sinkhole and Quriyat.
Five days: the Grand Mosque and Jabal Akhdar, Jabreen, Bahla and Nizwa, Wadi Bani Khalid and the Wahiba Sands, turtles at Ras Al Jinz, and the coast road back to Muscat.