Flower by the wayside

Again went for a walk up the hill to old Kefalos. On the way we passed oleander, poppies, aloe vera,thistles and many others. This plant was growing on the hillside and I have no idea what it is (any ideas?) Cut into the rocks where little shelters with a wire run for chickens and tiny little patches of ground with a few veg growing. Don't fancy having to water these, quite a climb and probably have to bring water with them,.