One kilometre out of town on the road to Estellencs, the Torre des Verger is a 1579 talayot (watchtower), an image you'll see on postcards all over the island. It's one of the most crazily sited structures on Mallorca – one step further and it would plunge into the Mediterranean far below. Climb to the top, fighting off vertigo as you proceed, and scan the horizon for yachts in the water from the place where sentinels once warned of pirates.