In the sun-baked deserts of the Hejaz region in Saudi Arabia, the hidden gem of Al-'Ula awaits. This frontier town was once a gateway to the muslim holy sites and straddled the Ottoman railway that linked Damascus to Medina. Now the railway is in ruins, but the surrounding landscape is as it always was: sublime. Ancient petroglyphs adorn the striking rock formations. Here, my guide Khaled leads the way past 'Elephant Rock'