Lago di Vico fills the crater of an old volcano in the Cimini hills, north of Rome, and it is one of the best-preserved volcanic lakes in Italy. The slopes around it are covered with beech and chestnut forest, and the lake is a nature reserve, with herons and grebes in the reeds. It sits a short hop from the lake, between Caprarola, Canepina and Carbognano, in a landscape of hazelnut orchards and woods.
Caprarola has one of the most extraordinary buildings of the Renaissance. The Palazzo Farnese, designed by Vignola for Cardinal Alessandro Farnese, is a pentagonal fortress-palace with a spiral staircase, frescoed rooms and gardens, standing at the top of a straight street that climbs through the village. It is a monument to the power and taste of one of Rome's great families.
The Cimini hills are the heart of Italy's hazelnut country, and the orchards cover the slopes in neat rows. In autumn, the harvest is in full swing, and the smell of roasting nuts fills the air. Canepina is known for its chestnuts, and Ronciglione for its carnival, one of the oldest in Italy.
For a swim, Lago di Vico has stretches of shore where bathing is allowed, and the water is clean and calm in summer, with the wooded crater rim all around. Parts of the lake are strictly protected, so look for the signs before wading in.
The roads over the Cimini hills, the Via Cimina among them, wind through beech woods and hazel orchards with a good rhythm and modest traffic outside summer weekends. Ronciglione is your refuelling point; its old centre, set above a ravine, is worth a slow walk afterwards.