Arrive in the Piazza Duomo by escalator and make a beeline for the Duomo, which shuts at 12:30 for a 2.5-hour lunch break. Arezzo's duomo, properly called San Donato after the local saint who lost his head (see Pieve di Santa Maria, bellow), is a massive structure which must hold records for the number of years it took to build. Started in 1278, it was 1515 before the interior was finished, 1859 before the first bell rang in its campanile and 1935 before the finishing touches were put in the façade. It's rather gloomy, mainly because of the stained glass in its windows, a rarity in Italy and very daring for its time. There are della Robbia terracottas in the chapel of Madonna della Conforta on the left, the marble tomb of bishop Guido Tarlati (possibly designed by Giotto) on the right, and close by, a fresco by Piero della Francesca of Mary Magdalen holding a crystal container. Look to your left as you leave the duomo to see the crenellated 16C Palazzo Comunale (town hall) with its matching tower.
From Piazza Santa Trinita turn left into Via Porta Rossa, lined with 14C mansions. Continue to the Loggia del Mercato Nuovo. 'Cashmere' and 'leather' are loosely interpreted here but the merchandise is fun and colourful. Find the Porcellino ('Piglet') Fountain on the south side of the Mercato and touch its nose for good luck. With Porcellino on your right, walk along Via Por Santa Maria to Ponte Vecchio. Until 1218, the wooden bridge at the site of today's Ponte Vecchio ('old bridge') was the only means for Florence's population of 30,000 to cross the river; a flood in 1345 prompted its reconstruction in stone. In 1944, the retreating Germans destroyed all Florence's bridges save this, apparently thanks to an express order from Hitler. The shops on the bridge were traditionally occupied by butchers and fishmongers who dumped their waste into the river, and by tanners who soaked their hides in it. Their Medici landlords eventually evicted them in favour of jewellers and goldsmiths (who paid twice the rent). The word 'bankrupt' originated here: when a merchant was unable to pay his debts, the table he used to display his wares (banco) was broken (rotta) by soldiers.
Exit the Piazza by Via Seteria on the south-west side and follow it downhill and around to Pieve di Santa Maria. An ornate 12C Pisan-style church topped by a bell tower, the already tall façade of Pieve di Santa Maria is made to seem even more so by the narrow street and the increasingly narrow spaces between the columns on its three tiers of arcades. The squared-off bell tower, added 200 years after the church's construction, is known locally as the 'tower of 100 holes' for obvious reasons (although there are actually only 40 double windows). The worn carvings above the main portal represent each of the months of the year (the decidedly un-Christian two-faced god Janus stands for January). The interior is fairly austere but features an altar of the Madonna and Saints by Sienese Piero Lorenzetti. The saint on the left is Arezzo's own St. Donatus, martyred in 304AD during an anti-Christian period. His remains are in the church's crypt, enclosed in silver and gold reliquary in the shape of a bust. He earned his right to be here: legend has it that he was beheaded on top of Arezzo's hill; his head rolled away and this church was built where it stopped. The façade of the church faces Via dei Pileati, which forms the top end of Arezzo's main shopping street, the pedestrian-only Corso d'Italia. Across the street is the Casa Museo Ivan Bruschi, an Aladdin's Cave of art and antiques collected by the man who founded the antiques fair.
Turn left as you leave the church and follow Corso d'Italia downhill. Follow the signs to the Basilica di San Francesco by turning right on Corso Cavour. The Basilica of San Francesco, built around 1320, was nothing special before the Bacci family commissioned Piero della Francesca to paint the choir. The façade is dead plain to the point of shabbiness, and in fact is missing the finished stone façade detailed in its original plans. You can see the famous frescoes fairly well from behind the cordon, 10m/33 feet away, but to enter the chapel itself for a close-up look you'll have to have booked ahead. There are plenty of choices around here for lunch
Continue along Corso Cavour to the Badia delle Sante Flora e Lucilla, passing Via Guido Monaco which leads in from the train station. Guido Monaco, aka Guido d'Arezzo, invented musical notation in 1025 at age 34. While a monk in Ferrara he had difficulties memorizing the Gregorian chants and designed a crib sheet with staffs as shorthand symbols for notes. His colleagues at the abbey were appalled but not so the rest of Europe. The bishop of Arezzo invited him to conduct the cathedral's choir and so he did, continuing his work in musical mnemonics and developing the 'do-re-mi' system on the side. Its opening hours are inconvenient but if you find the door open duck into the Badia di SS Flora e Lucilla to see a masterpiece of trompe l'oeil: an entire cupola painted in impeccable perspective that makes a very shallow dome look enormous. Its creator was master illusionist Andrea Pozzo, who worked here in 1702 after completing his even more dramatic work in the church of St. Ignazio in Rome. The effect is best viewed from a small bronze marker in the aisle near front pews. Follow Via Cavour as it curves to the north. Make a slight jog to the right crossing Piaggia di Murello and, with Santa Maria in Gradi on your right, turn right into Via XX Dicembre. Santa Maria in Gradi is 12C, rebuilt in the 16C and contains a della Robbia terracotta of the Madonna della Misericordia. The house that once belonged to Vasari at #55 is now a museum, Casa Vasari, effusively but not skillfully decorated by the architect/painter/author, Giorgio Vasari, himself. Turn right at the end of Via XX Dicembre, then left following signs to the church of San Domenico. The main attraction in the somewhat gloomy 13C San Domenico is a crucifixion scene by Cimabue, one of the earliest Renaissance artists, painted when he was very young. Exit the church and turn right to follow Via Madonna Laura back to Piazza Duomo.