Today, the trulli of Alberobello are a Unesco World Heritage site, although many people have never heard of these ingenious structures.Fifty-six kilometres south of the Puglian port city of Bari, on the heel of Italy's boot, I could see several small stone huts with conical rock-covered roofs scattered among the olive trees on both sides of the road. Reminiscent of teepees or tiny forts, these structures were unlike anything I'd ever encountered.