Lucca Cathedral in Piazza San Martino, the lovely 11th century Duomo, in a typically elaborate Pisa-Romanesque architectural style.
Piazza San Martina and Lucca's Duomo, with monthly antique market (the 3rd Saturday/Sunday of each month).
Inside the free-to-enter cathedral are some interesting artefacts (though no photos allowed!), such as the Volto Santo, a revered, black, 13th century crucifixion effigy set on a more modern and very unusual sparkly, circular cross. There are several spectacular paintings in the cathedral (which you may have to illuminate by paying .50c to switch on the power) including Ghirlanaio's Madonna and Saints. and Pisano's Journey of the Magi. Bugbog was, however, not impressed by the pay-to-enter tomb of Ilaria del Carreto and its marble portrait of Guinigi's bride.
A detail from the complex facade of the Duomo.
Bike rentals in Lucca cost about €2.50 per hour or €12.50 per day and the place is perfect for cycling, just remember to get a bike lock.