Why Rennes works so well as a base

Rennes station sits on the southern edge of the city centre, around fifteen minutes on foot from the cobbles of Place des Lices, and regional trains fan out from it across Brittany in almost every direction. You do not need a car to reach a château, a walled port or a garden – most of the trips below take under an hour each way, and a day return costs little more than a decent lunch.

Two habits make everything easier. Check the timetable the evening before rather than trusting a leaflet printed months ago, because regional services change with the seasons. And decide your return train before you set off: Sunday and public holiday services are noticeably thinner, and on quieter lines the last train back can leave surprisingly early. Buy your ticket at the station or in advance, and if you are handed a paper ticket, remember to validate it in the machine where signs tell you to.

Vitré: medieval lanes in twenty-five minutes

The quickest taste of old Brittany is Vitré, roughly twenty-five minutes east of Rennes. The station is a ten-minute walk from the castle, a looming thirteenth-century fortress with towers, a drawbridge and a small museum inside. Below it, the streets are a jumble of timber-framed houses, granite arcades and steep slate roofs, at their best along the rue de la Baudrairie and around the place du Château.

Allow half a day rather than a full one. Climb to the Promenade du Château for the view over the Vilaine valley, look inside the church of Notre-Dame, and finish with coffee on the square. Because the journey is so short, Vitré also makes a sensible wet-weather or half-day option if you are saving a longer trip for later in the week.

Saint-Malo: ramparts, beaches and the sea

Saint-Malo is about fifty minutes north, and the station is a twenty-minute walk from the gates of the intra-muros. Once inside, the whole town is your circuit: a mile or so of ramparts to walk, sea on one side and grey rooftops on the other, with the castle housing the city's history museum.

Time your visit with the tides. At low water you can walk out across the sand to the island of Grand Bé; at high tide the same spot is open sea. The beaches – the long Sillon, and the Plage de Bon-Secours with its seawater pool – are pleasant even out of season, and there are plenty of crêperies to shelter in when the weather turns.

If you would rather see the abbey at Mont-Saint-Michel, get off one stop earlier at Dol-de-Bretagne, roughly thirty-five minutes from Rennes, where a seasonal shuttle covers the final stretch. It makes for a longer, fuller day, so check the shuttle times before you commit.

Dinan and Combourg: château country

Dinan, around fifty minutes away on direct services, is the pick of the inland towns. The station sits above the centre, so you walk downhill – remember that the climb back up at the end of the day is real, and there is a bus if you would rather not. Inside the ramparts, the place du Guesclin, the basilica and the half-timbered houses are all within ten minutes of each other. The best walk is down the steep, cobbled rue du Jerzual to the little port on the Rance, where seasonal boats run up the estuary.

Combourg, on the same corridor and about forty minutes from Rennes, suits a quieter afternoon. Its château rises straight out of a lake, and inside you can see the rooms where the writer Chateaubriand spent his childhood. The town itself is small: an hour or two in the château, a wander around the water, and you are ready for the train back. Combine it with Dinan only if you start early.

Vannes and the Gulf of Morbihan

With a whole day to spare, head south-west to Vannes, roughly an hour and twenty minutes away. The old town is still wrapped in its ramparts, and the Jardin des Remparts, the old wash houses along the river and the covered market make an easy, aimless morning. La Cohue, the gallery in the former market hall beside the cathedral, is a good rain plan.

From the port, seasonal boats head out into the Gulf of Morbihan, the scatter of islands that gives the department its name. Even without a boat, the waterfront and the gardens below the walls are worth the journey. As this is the longest of the day trips here, start early and check the last train before you leave Rennes.

Practical pointers for a car-free day out

• Check the timetable the day before. Seasonal changes are common, and some services run only in summer.
• Buy before you board. Small stations often have no ticket office, so sort your return ticket when you leave Rennes.
• Plan the last train. Sundays and public holidays are sparse – set an alarm rather than hoping.
• Expect a walk. Most stations here are ten to twenty minutes from the sights, and cobbles punish the wrong shoes.
• Bikes travel free but spaces are limited. In summer, some peak services require a reservation, so ask when you buy your ticket.
• Pack a picnic. A bakery or market near the station is cheaper and often better than a tourist-menu lunch, and leaves more time for the train.