The old town spreads down the ridge from the abbey in a tangle of stepped alleys, vaulted passages and small piazzas. Stone houses are built directly into the soft local tufa, and most of them have a cantina or sottano dug back into the hill — the cool underground vaults where families once stored wine, oil and grain. A handful are open to visitors during the August festivals and the Carnevale.
There is no fixed route through it. Wander uphill from Porta Sant'Angelo, take whichever lane looks promising, and you will end up either back at the abbey or out on one of the belvederes that ring the town. Half an hour is enough to get the sense of it; longer if you stop for a coffee in one of the few small bars along the main street.