2 hours from Muscat is Wadi Mistall (4x4 car is needed). Here you can make a 2 days loop trek in eastern Ahkdar.
This trek is very difficult because the mountain is very high (2000m), very steep and there are a lot of difficult passages. And you have to bring a lot of water and food which makes you carrying heavy bags.
The trek is 2 days long : We've started the trek at 8.30am and we were back the day after at 3.30pm ! So this trekk is generally recommanded to experienced trekkers. But we aren't expert trekkers and we did it ! so you can do it as well I think, you just need a good motivation.
Note : you can do this trek yourself refering to the trek numbers w25, W24a, w24b in the Oman trekking explorer guide
Sunday, April 1