Cigarette dangling from her mouth, the punkish Italian student ambling along the pavement fires me a look that says: "You better not be photographing me, mister." I'm not, actually - I'm just waiting for her to pass so I can snap the thing that has piqued my interest: a surreal twist on Johannes Vermeer's Girl with a Pearl Earring. Clad in a familiar blue and yellow headscarf, Vermeer's muse is wearing a snorkel mask. It's the kind of quirky, colourful piece of art that's flourishing on the streets of Florence.
For centuries, tourists have flocked to the Tuscan capital to marvel at its Renaissance treasures, but for those who suffer from "gallery fatigue", overwhelmed by the mind-blowing array of "must-see" attractions - and all the claustrophobia-inducing crowds, queues and selfie sticks - you can increasingly get your Florentine art fix al fresco.
Tags, murals and graffiti pepper walls and buildings in the city's bustling central core, but for the best stuff, head to the Oltrarno - the more chillaxed southern side of the River Arno. After crossing the iconic Ponte Vecchio (the one Florentine bridge to survive destruction from retreating Nazi forces in 1944), you'll find a tangle of streets sprinkled with eye-catching street art.
My tip: take your first left onto Via de' Bardi, a portal into the bohemian San Niccolo district. At first glance, it's an unremarkable stretch; its snaking rows of four-storey apartment buildings, flanking either side, evoking an air of faded grandeur. Occasionally, a scooter or car will whizz by. But, in general, noise levels are lower than in some big-name galleries. And every 50 metres or so, there's something to browse, a glimmer of creativity, often covering the gas and electricity panels on the buildings' shabby brick facades.
You'll see cartoons of cats with masquerade masks, matchstick men chasing red balloons, and several boasting the aquatic-themed hallmarks of Blub. Famed for his 'L'arte Sa Nuotare' - or 'Art Knows how to Swim' - project, Blub (whose real name is as much a mystery as Banksy's) has added snorkel masks to a string of classics, including the Girl with a Pearl Earring, da Vinci's Mona Lisa and Piero della Francesca's Duke and Duchess of Urbino (the 15th century original of which graces the city's hallowed Uffizi Gallery).
Someone has, rather mischievously, placed a Venetian mask on Blub's take on Botticelli's Birth of Venus. Pope Francis, David Bowie and Gabriel Batistuta - a goalscoring legend of Florence's soccer club, Fiorentina - are among the contemporary characters to receive the 'Blub' treatment.
So, too, has Clet Abraham, perhaps the most revered 'guerilla' artist in Florence. A portrait of Abraham, in a snorkel mask, graces the exterior wall of his studio on the corner of Via dell' Olmo and Via di San Niccolo (which Via de' Bardi blends into). In the image, a grinning Abraham is holding a sticker of a figure, in scuba diving gear, hauling away a 'no entry' road sign. It's a nod to Abraham's own work.
This 40-something French-born maverick is known for pedalling around the city at night, festooning signs with whimsical vinyl stickers. Some are thought-provoking and political. Others pay homage to the city's artistic heritage (think: 'one way' signs capped by halo-blessed angels, and 'no entry' signs being chipped away, sculpture-style).
The Florentine authorities have peeled away quite a few, but dozens of Abraham's stickers remain, especially in San Niccolo and the neighbouring Santo Spirito district, east of Ponte Vecchio. There's even a fishbone-shaped one-way sign outside his studio, in which you can peruse and purchase replicas of his work - which has appeared on street signs across Europe. You might even see the man himself beavering away. Hours could be whiled away, prowling the Oltrarno for street art, but when you've had your fill, there are some lovely cafes and enotecas (wine bar-bistros) to hang out in. And you musn't miss the hilltop Piazzale Michelangelo. Flaunting a panorama that takes in the Arno, the city's skyline (most noticeably the giant dome of the Duomo) and a backdrop of Tuscan hills - it's arguably the finest vantage point in Florence. On a sunny day, no artist, however talented, could do this view justice.
Qantas and Emirates fly from Sydney and Melbourne to Florence via Rome and Dubai.
A day trip to Florence is included on Collette's Spotlight on Tuscany tour - which comprises a seven-night stay in the nearby Tuscan spa town of Montecatini Terme, and side trips to Siena, Lucca, Pisa and San Gimignano. Tours are priced from $US1349 ($A1749) per person; www.gocollette.com
Steve McKenna was a guest of Collette