The Aventine

The Aventine is one of Rome's seven hills and, for visitors, its best-kept open secret: a calm, residential plateau of villas, gardens and early churches just above the Circus Maximus, a world away from the crowds below. Its most famous sight is barely a few centimetres wide. At the end of Piazza dei Cavalieri di Malta, a square designed by the engraver Giovanni Battista Piranesi, the great green door of the Priory of the Knights of Malta has a keyhole; look through it and you see an avenue of clipped hedges framing, in perfect miniature, the dome of St Peter's Basilica in the distance. It is free, and the queue to peer through it is part of the ritual. A few steps away, the Giardino degli Aranci, the Orange Garden, officially Parco Savello, is a walled park of bitter orange trees ending in a terrace with one of the loveliest views in the city: across the bend of the Tiber to Trastevere, the Jewish Ghetto, and the domes of the centro storico, with St Peter's on the horizon. Between them stands Santa Sabina, a fifth-century basilica of serene, light-filled simplicity, with ancient Corinthian columns and carved cypress-wood doors among the oldest of their kind. Nearby Sant'Alessio adds a Romanesque bell tower, and on the slope below, the city's Rose Garden opens in spring with hundreds of varieties. All of this is free, and the hill is a favourite with Roman couples, wedding photographers and anyone looking for a quiet hour.

The classic route takes about an hour and works best in the late afternoon. Start at the Circus Maximus, the grassy outline of ancient Rome's great chariot-racing stadium, and climb Via di Valle Murcia or the Clivo di Rocca Savella, a stepped medieval lane, up to the Orange Garden. Linger at the terrace for the view, then walk a hundred metres along Via di Santa Sabina, look into Santa Sabina and its cloister if open, and continue to Piazza dei Cavalieri di Malta for the keyhole. The line moves steadily; when your turn comes, put your eye close to the hole and wait a moment for it to adjust. Sunset at the Orange Garden is the high point, though the terrace gets busy at that hour.

Santa Sabina is worth more than a glance. Built in the fifth century and later entrusted to the Dominican order, it shows what an early Christian basilica looked like before the Baroque: clean lines, high windows filled with selenite, and the wooden doors whose panels include one of the earliest surviving depictions of the Crucifixion. Churches here keep their own hours and close in the middle of the day, so check before you climb. The Rose Garden, on the slope facing the Palatine, opens only for a few weeks in spring and occasionally in autumn.

From the Aventine you can descend toward Testaccio, the traditional working-class neighbourhood that is now one of the best food districts in the city, with its covered market and old-school trattorias. In the other direction, the Bocca della Verità, the Mouth of Truth, stands in the portico of Santa Maria in Cosmedin at the foot of the hill, a short walk from the river. With the Palatine and Circus Maximus next door, the Aventine also makes a gentle, shaded counterpoint to a morning at the Colosseum. On a first visit it is easy to overlook, which is exactly why it feels special when you get there.