Nakhl fort, dating from the 16th and 17th centuries, Batinah region, western Hajar, Oman, Middle East

Inside the walls of the restored fort of Nakhal in the Western Hajar mountains of Oman, Middle East

Inside the walls of the restored fort of Nakhal in the Western Hajar mountains of Oman, Middle East

Inside the walls of the restored fort of Nakhal in the Western Hajar mountains of Oman, Middle East

Nakhl fort, Batinah region, western Hajar, Oman, Middle East

View from Nizwa Fort to western Hajar Mountains, Nizwa, Oman, Middle East

Wadi Bani Awf, Djebel Akhdar, Western Hajar mountains, rising to 3000m, Oman, Middle East

Oman's Grand Canyon, situated in Jebel Shams, at 1900m, Western Hajar, Oman, Middle East

View from Nizwa Fort to western Hajar Mountains, Nizwa, Oman, Middle East

Nakhl fort, dating from the 16th and 17th centuries, Batinah region, Western Hajar, Oman, Middle East

A hiker traversing a zip-wire (aka flying fox) on the Via Ferrata hike in Snake Canyon, part of Wadi Bani Auf in Jebel Akhdar of the western Hajar mountains in Oman.

A hiker traversing a zip-wire (aka flying fox) on the Via Ferrata hike in Snake Canyon, part of Wadi Bani Auf in Jebel Akhdar of the western Hajar mountains in Oman.

A hiker traversing a zip-wire (aka flying fox) on the Via Ferrata hike in Snake Canyon, part of Wadi Bani Auf in Jebel Akhdar of the western Hajar mountains in Oman.

A man doing the Via Ferrata hike in Snake Canyon, part of Wadi Bani Auf in Jebel Akhdar of the western Hajar mountains in Oman.

Hikers near Snake Canyon, part of Wadi Bani Auf in Jebel Akhdar of the western Hajar mountains in Oman.

Hikers doing the Via Ferrata hike in Snake Canyon, part of Wadi Bani Auf in Jebel Akhdar of the western Hajar mountains in Oman.

Hikers doing the Via Ferrata hike in Snake Canyon in Jebel Akhdar of the western Hajar mountains in Oman.

A hiker starting the Via Ferrata hike in Snake Canyon, part of Wadi Bani Auf in Jebel Akhdar of the western Hajar mountains in Oman.