Bergamo has two halves: the walled Città Alta on its hill, and the lower city around Porta Nuova and the railway station. Sleep in the upper town to walk out onto Piazza Vecchia. Stay down below if you have trains or the airport bus to catch.
Piazza Vecchia is the centre of Città Alta. Palazzo della Ragione, the Campanone and the cathedral square are a short walk apart. Via Colleoni runs west toward the Citadel and Colle Aperto. The Venetian walls circle the hill, and the gate at Porta San Giacomo is a fine way up on foot, but the climb is steep.
Città Bassa runs from the station up Viale Papa Giovanni XXIII to Porta Nuova and the Sentierone. Stay here for early trains and the Airport Bus. East of the centre, Borgo Pignolo leads to the Accademia Carrara and GAMeC. Borgo Santa Caterina, next door, has local shops and restaurants that fill up in the evening.
Bergamo has two funiculars. One climbs from the lower city to Piazza Mercato delle Scarpe. The other goes on from Città Alta up to San Vigilio. A room by Piazza Vecchia saves the ride up after dinner, but its old lanes are harder going with luggage than the streets by the station.
Walk the walls and the upper town in spring or early autumn. Summer afternoons get hot, and November is the wettest month. Direct regional trains run to Milan, but leave time to get down from Città Alta before you catch one.