Right in the southeastern corner of the Arabian Peninsula, facing the Gulf of Oman in the north and the Arabian Sea towards the southeast, lies the Sultanate of Oman. The interior of Oman is largely arid and rocky desert country, with mountainous terrain in the north and the southeast.
Most prominent are the Al Hajar Mountains stretching out across the north of Oman. Here you will find the highest mountains in the East Arabian region, and Oman's highest peak Jabal Shams (2980 m). There are wonderful hiking possibilities in both the Eastern and Western Hajar Mountains, in the high Jabal Al Akhdar range and along the rim of Jabal Shams. Some parts are pretty rough going, passing along deep canyons and gorges. Other trails connect remote and beautiful wadi's (oases).
An interesting option is hiking (and bird watching) on the remote Musandam Peninsula, a rugged mountainous enclave of Oman in the United Arab Emirates (UAE) near Dubai, on the tip of the Arabian Peninsula.
Apart from the mountains, you can set out to explore the desert with camels, for instance in the Wahiba Sands south of the capital Muscat.
When visiting Oman, and for hiking in particular, avoid the extremely hot months of June, July and August.