San Marino's nine castelli, and which are worth the detour

San Marino has no counties or boroughs in the usual sense. It has nine castelli, which is what the Sammarinese call their municipalities, and the word is no affectation. Almost every one grew up around a castle, and several still keep the tower or its ruins. It’s the clearest way I know of showing that the country doesn’t end on the ridge of Mount Titano, even if most day-trippers never come down from it.

Nine municipalities in 61 square kilometres

Together the nine add up to 34,167 residents on 30 June 2026 and 61.19 km², the sum of the figures the government gives for each. Every castello has its Giunta di Castello, chaired by a Capitano di Castello, which looks after local matters, a little like a parish council with more clout. The table above lists all nine from most to least populated.

What surprises people is that the capital doesn’t win on numbers. The City of San Marino, with its towers, Palazzo Pubblico and museums, has 4,158 residents. Serravalle has nearly three times as many and Borgo Maggiore almost three thousand more. The real country lives below, in the valleys, while the city on top is mostly institutions, shops and visitors.

Why five arrived at once in 1463

The castelli explain the map of San Marino. In 1463 San Marino joined Pope Pius II’s league against Sigismondo Pandolfo Malatesta, lord of Rimini, and was rewarded with Serravalle, Domagnano, Fiorentino and Montegiardino. That same year Faetano asked to join, and its own government page says it surrendered of its own accord to the Sammarinese troops. The borders have stayed put ever since.

Chiesanuova is the exception I like to mention. Its people asked to join on 10 February 1320, when the place was still called Busignano, and it only took its current name in the 16th century. The coats of arms of the last castles to join sit on the front of the Palazzo Pubblico, a detail almost nobody notices while crossing the square.

The ones I’d see beyond Titano

Borgo Maggiore is the obvious one, because the cable car drops straight into it and because it was the Mercatale, the market town. Given an afternoon and a car, though, I’d head for Montegiardino. The government describes it as the smallest and most intact of the nine, a maze of tight lanes with its wall, the old tower and a gate reminiscent of a drawbridge. It belonged to the Counts of Carpegna and then to the Malatesta, who strengthened the fort, and once it passed to San Marino the stronghold was turned into houses.

Faetano would be my second stop. It sits on a gypsum spur high above the Marano stream, carries a beech tree on its crest because that’s where its name comes from, and has a riverside park with a path for walks out of the village, plus Lake Faetano, a small fishing lake by the border. Neighbouring Fiorentino boasts three castles, and at Pennarossa you can still make out the foundations, the keep, the wall walks and a cistern cut into the rock. It also remembers the aviator Gianni Widmer, who made the first flight over San Marino in 1913.

Chiesanuova and Acquaviva are for anyone after countryside. The first has 114 hectares of woodland and the Molarini watermill beside the Fosso Canepa, one of the few with its walls still standing. The second keeps the tradition that the saint entered here and baptised converts in the spring below Montecerreto, where La Pineta park now stands. I’ve gathered the walks through these valleys in walking trails in San Marino.

Serravalle, Dogana and the San Marino that works

Serravalle is the largest by both measures, and Dogana and Falciano sit inside it. It has a medieval tower and an old pedigree, turning up as «serra vallum» in a charter of 962, but today it’s mostly industrial estates, stadiums and shopping centres. Dogana is the way in from Rimini along the dual carriageway, and it’s where you notice there’s no border with checks.

Domagnano, between Borgo and Serravalle, is farmland, with 70% of its land given over to olives, vines and wheat according to its page, and a carnival of floats the locals take very seriously. I wouldn’t put it on a first visit, but you pass through it on the Rimini bus.

Getting between castelli

Without a car, AASS line 47 connects the City with Borgo Maggiore, Domagnano, Serravalle and Dogana, and the SMUVI on-demand service reaches the rest from the existing stops, booked by app or phone. All internal buses were free from March to 30 September 2026, so check the fare from October before you set off. Lines and times are in getting around San Marino. By car the distances are short, and the hard part is parking at the top, not at the bottom.