On Route 107dir, 29 km south of Barietta. ‘The most perfect castle in Italy’ it is said – the most perfect geometrically, that is. It was built as a mere hunting-lodge but no building could more decisively express the power and authority of the Swabian Emperor Frederick II (known as Stupor Mundi, the ‘wonder of the world’ for his restless ambitions, intelligence and enormous building programmes).

The Castel presides over a smiling landscape of meadows and olive woods, a refreshing scene after the treeless, waterless rock-bound coast. Its symmetry – eight sides and eight towers, each with eight walls, all fitted into a precise circle – gives it a strict severity, not as disagreeable as that of some Puglian churches because it is of pale stone and seems to be lightly poised on a hillock which might have been made for it. Closer inspection reveals a fascinating mixture of classical, Gothic and Moorish styles. All is open to the public, but the interior is quite bare. The mound around it is a deservedly popular picnic spot.