There he offers 40 flavours daily, from saffron to pine nuts and pistachio to peach, though the selection is constantly changing.
He even has one he calls Michelle, named after the former First Lady of the United States. And he’s more than happy to tell you the story of how it came to be.
It seems, two years ago, Mrs Obama was scheduled to visit Italy and the San Gimignano region, prompting local officials to suggest Sergio serve her some of his famed ice cream
Sparking his creative juice, he came up with a new flavour – a blend of almonds, honey, orange and fig. Unfortunately, he was stood up, as a change in travel arrangements meant the first lady never arrived.
“Don’t worry, I say, whenever she finds time the gelato is ready,” he laughs.
Sergio is one of the characters of this small Italian town that was once an important stop-off for pilgrims travelling to or from Rome on the Via Francigena.
Encircled by 13th-century walls, its old town centres on the Piazza della Cisterna, a triangular square lined with medieval houses.
The Patrician families who controlled the town at its height built more than 72 tower-style homes, each trying to outdo the other in grandeur.
Only 14 have survived but help San Gimignano retain its medieval atmosphere and appearance.
The tallest remaining tower, the Torre Grossa, offers stunning views of the surrounding Tuscan countryside. Its original internal staircase, supplemented by some modern editions, requires some effort to climb, but it’s worth it.
The town’s medieval character is on display from the restored bell tower while the rolling hills appear to go on forever.
Equally spectacular is the Duomo di San Gimignano, a 12th-century church with frescoes by Ghirlandaio, the Italian Renaissance painter born in Florence, in its Santa Fina Chapel.
Less known than nearby Siena and certainly less of a tourist drawcard than Rome, San Gimignano is often overlooked by both independent travellers and tour companies.
But a growing number of companies, such as Trafalgar, are opting to include it on selected itineraries.
San Gimignano also benefits from being just a one-hour drive from Florence and an acceptable three-hour drive to Venice, one of the obvious must-do destinations of any Italian tour.
It’s hard to imagine just what can be said about Venice that hasn’t already been said, both good and bad.
The number of people. Even in the so-called off-seasons, Venice is still a crowded place to visit.
Only 55,000 people still live within the original 100 islands in the lagoon in the Adriatic Sea, but they host 30 million tourists each year.
Head out into the streets early in the day and it’s relatively easy to get around. But come mid-morning the key tourists spots such as the central square, the Piazza San Marco, are teeming.
Then there’s the increasing risk of flooding. Traditionally, water levels rose and spilled over into the streets about 12 or 13 times each year. Now it can happen more than 100 times.
The constantly rising waters have become an issue for locals and tourists alike, with authorities currently working on a major infrastructure plan to construct a series of gates in the lagoon, which can be raised to stem the tidal flows.
One local business has embraced the phenomenon known as aqua alta, when a high tide combines with low atmospheric pressure and a wind blowing off the Adriatic to ensure many buildings become inundated. Libreria Acqua Alta, which calls itself the most beautiful bookshop in the world, keeps all its wares high off the ground and uses gondolas (what else?) to display many of its texts.
The shop is one of the rewards on offer, if you choose to venture somewhat off the well-trodden paths and down the smaller lanes, places that help Venice remain a magical destination.
Away from the main tourist drawcards is Burano Island, best known for its famed lace production and its colourful buildings, houses painted in bright greens, blues, reds and yellows.
It also has a leaning bell tower (Pisa, eat your heart out) and offers some respite from the crowds in the centre of Venice.
Many of the locals have turned the lower floors of their homes into stores selling souvenirs of lace and Murano glass to the passing visitors, yet feel completely at ease in hanging out their washing right alongside.
Getting there: Rome is about 23 hours flying time from Adelaide with connections available through Doha and Dubai.
San Gimignano is 45km from Siena and 270km or three hours from Rome.
Venice is about 525km north-east of Rome. Fast train connections take about three hours.
Staying there: Accommodation in Rome varies greatly depending on how close you want to be to the ancient city. Tour groups can secure premium spots and better prices.
There are fewer options for staying close to San Gimignano but some stunning locations are available. Check out the Relais Cappuccina, where rooms start from $A190 a night for a twin room.
In Venice, stay on the islands if the budget allows. But prices can be steep in peak season. The hotel Bellini Venezia is an example of many on offer along and near the grand canal. Prices start from about $A450 a night.
Playing there: Treat yourself to a gelato at Gelateria Dondoli in San Gimignano. I recommend the pistachio.
In Venice, take a boat ride down the Grand Canal but be careful of the water taxi prices, which can be high. For the more romantic there’s also the gondolas.
Take time to visit some of Venice’s small alleys and streets – there are some beautiful sites.
Take a boat ride to Burano Island. It takes about 45 minutes but offers a relaxing break from the hustle and bustle of Venice itself. Enjoy a leisurely lunch at one of the island’s many cafes or restaurants.
Be careful if you’re in the market for some of the famed Murano glass. It’s for sale everywhere in Venice but it’s also estimated that up to 60 per cent of what’s on offer is actually fake and comes from China.
The writer travelled as a guest of Trafalgar.
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