Complex sentence: The three southern ridges are quite steep as they drop away to the valley of the River Tummel, one goes initially west and then south taking in the craggy and rocky slopes of the outlying top of Càrn Fiaclach.
Split into simpler sentences: The three southern ridges are quite steep as they drop away to the valley of the River Tummel. One goes initially west and then south taking in the craggy and rocky slopes of the outlying top of Càrn Fiaclach.