Sailing the River Nile is a bucket-list experience. Since the first tourists travelled down the river in 1869, it has attracted visitors enthralled by Egypt’s pharaohs, prophets and pyramids. The world’s longest river flows through 11 African countries for 4,100 miles before spilling out into the Mediterranean, but it’s the Upper Nile, which snakes through southern Egypt, that offers the most cruise itineraries. These visit some of the…