Half an hour from Rome there's a small town where, once a year, water turns into wine. It's no miracle, just a custom more than a century old: at the grape festival in Marino, in the Castelli Romani hills south-east of the Italian capital, the fountain in the main square pours wine instead of water.

The grape festival, the Sagra dell'Uva, is being held for the 102nd time this year. It was started in 1925 by poet and journalist Leone Ciprelli, who wanted to bring the harvest, the wine and the town's history together in one place. Wine from the fountain has been part of the festival since the very first edition.

A fountain for the victory at Lepanto

The main star is the Fountain of the Four Moors in Piazza Matteotti. It was built in 1632 to mark the victory of Marcantonio II Colonna at the Battle of Lepanto - the 1571 naval battle in which the Christian fleets defeated the Ottoman one. The fountain has three levels: eight stone sirens at the bottom, four human figures above them and the Colonna family coat of arms on top. It was damaged in the Second World War, then restored and moved.

If you're planning to go, the window is short. The main moment is on Sunday, 4 October, at 17:30, with a second chance on Monday, 5 October, at 18:45. On Sunday the programme opens with guided tours and a religious ceremony blessing the grapes at 10:30, and in the early afternoon a historical procession winds through the streets, re-enacting Colonna's return as commander of the papal fleet. Throughout the festival there's a food village and stalls with Italian farm produce. Entry to the celebrations, processions and performances is free.

What else to see

Marino's old centre is worth a visit beyond the festival: Palazzo Colonna, the Basilica of San Barnaba, the museums and underground spaces carved into volcanic rock. The Mithraeum is something special, with an exceptional Roman fresco of the god Mithras sacrificing a bull.

The rest of the Castelli Romani offers three more stops for a day trip: Castel Gandolfo above Lake Albano, with an elegant centre and the papal palace; Nemi by its small lake, historically tied to the cult of Diana and known for its strawberries; and Frascati, with historic villas and wines.

Marino can be reached by regional train from Rome's Termini station, or by metro line A to Anagnina and then Cotral buses. Extra shuttle lines run during the festival.

The Italians have turned a grape harvest into a tourist brand that has lasted a century. The Tikveš harvest festival in Kavadarci, Macedonia's wine heartland, has its own tradition and its own wine. What would it take for it, too, to become a reason for someone to buy a plane ticket?