All sport voice-over: this is bbc news. we will have the headlines for you at the top of the hour, which is straight after this programme. i'm alice morrison, an adventurer and writer. i've cycled across africa and run across the sahara. now i'm on the trail of a mysterious and forgotten arabian civilisation — the nabataeans. are we standing in the birthplace of written arabic? i think i would say that, yes. they were nomads who forged a rich civilisation here in the harsh desert conditions of western arabia from the fourth century bce.