Bring water," they said when I announced I'd be hiking the Sentiero dei Fortini (Trail of Little Forts). "There's nothing out there." The six-kilometre cliffside path linking the remains of three 19th-Century Bourbon military outposts was my fourth hike on this craggy Mediterranean island.

Somewhere along the rocky, wild rosemary-flocked path while dodging spiky prickly pears, I realised that I'd only seen one other human in two hours. And there were indeed no water sources, aside from a rustic fountain I'd encountered a kilometre back at Fort Mèsola.