Cardiff or Saint-Malo?

Cardiff's waterfront is tidal and brown, so a beach day means taking the train to Barry Island's funfair bay or heading to Penarth's pebbles. The better sand at Porthcawl and Gower is an hour or more away by car.

Saint-Malo is a real seaside town. The long Sillon beach runs from the walls towards Paramé, the Bon-Secours sea pool fills at every tide, and low water opens up a vast area of sand. Both seas are cold, so in either place you will spend more time on the sand than in the water.

Neither is a place you travel to for the food, but they are good in different ways. Cardiff has range. You get Welsh cakes and cawl in the Victorian market, neighbourhood bistros in Pontcanna and Canton, a long stretch of Middle Eastern and South Asian cooking on City Road, and good local ales in the pubs.

Saint-Malo is narrower but rooted in its region. Galettes with dry cider, kouign-amann and Cancale oysters eaten by the harbour wall are the things to have. Avoid the tourist crêperies inside the walls and eat in Saint-Servan or towards Cancale instead.

Cardiff gives you more to see. Cardiff Castle combines Roman and Norman walls with lavish coal-era interiors, the National Museum has a strong Impressionist collection, and St Fagans gathers buildings from all over Wales. Llandaff Cathedral and the Senedd add to that.

Saint-Malo's sightseeing comes down to the town itself. You walk the ramparts, visit the cathedral and the castle keep, and cross to Chateaubriand's grave on the Grand Bé at low tide. The granite town was rebuilt after 1944, and the corsair history is told more through statues than museums, so a day covers it.

Cardiff is the place for a night out. St Mary Street fills with groups at weekends, Womanby Street has small alternative bars and late venues, and students keep things going during term. On rugby international days the whole centre becomes a party.

In Saint-Malo, the evening usually ends with a drink after dinner in a wine bar or Irish-style pub inside the walls. It stays lively only on summer weekends, and for clubs you have to go to Rennes.

Both are good bases for the outdoors, but the landscapes are different. From Cardiff you can follow the Taff Trail up the valley, or drive about an hour to the Brecon Beacons and climb Pen y Fan across open moorland. That gives you hills and height, which Saint-Malo's flat hinterland does not have.

Saint-Malo is all about the coast. The GR34 path runs to Pointe du Grouin and the cliffs of Cap Fréhel, tides of up to 13m reshape the bay, and the Rance estuary is good for kayaking and sailing. You may also see seals off the islands.

Cardiff's day trips mostly work without a car. Caerphilly, one of the largest medieval fortresses in Britain, is about twenty minutes away by train, and Bristol and Bath, with its Roman Baths and Georgian crescents, are about an hour away across the Severn. You only really need to drive for Chepstow Castle and Tintern Abbey in the Wye Valley, and for the old ironworks and coal mine at Blaenavon.

Saint-Malo has the single grandest sight of the two in Mont-Saint-Michel. The abbey on its tidal island, half-timbered Dinan and the oyster stalls at Cancale are easiest with a hire car or a coach tour, though. Without one, your options are the train to Rennes, the boat across the estuary to Dinard's Belle Époque villas and, in summer, a ferry to Jersey.

Saint-Malo has the edge with children because the fun is on the doorstep. There are sandcastles below the walls, jumps into the Bon-Secours pool, pirate stories on the ramparts and the Grand Aquarium for wet days. Watch the fast incoming tides on the causeways.

Cardiff works well too, with Techniquest, the farm animals at St Fagans and rowing boats on Roath Park lake. It has no aquarium, though, and the beach means a train to Barry Island.

Both cities are easy on foot. Cardiff's castle, market, arcades and station are a few minutes apart, and Saint-Malo's walled town joins the beach promenade. The difference is beyond the centre. Cardiff's local trains run to Penarth, Barry Island, Caerphilly and the valleys, so you need a car only for the national park.

Saint-Malo has direct fast trains to Rennes and Paris and a boat to Dinard. Buses to Mont-Saint-Michel and the coastal villages are thin, though, and parking by the walls is hard in summer.

Cardiff is the better place to shop. Alongside the Queen Street chains and a department store, its glass-roofed Victorian and Edwardian arcades are full of independent record, book and vintage shops, and you can buy lovespoons and Welsh woollens as gifts.

Saint-Malo is mostly about Breton specialities, such as sailor tops, salted-butter caramels, faience and cheese, plus the produce markets. For fashion you have to go to Rennes.

Cardiff is a little easier on the budget. The national museums, including St Fagans, are free, and the train trips to castles and the coast are short and cheap. Hotel prices jump on big stadium days, so check the calendar before you book.

Saint-Malo is priced as a popular resort, and rooms inside the walls and by the beach are expensive in July and August. A galette with cider and the set lunch menus keep eating out reasonable, and spring and autumn bring prices down.

Cardiff is far ahead here. The Wales Millennium Centre is home to Welsh National Opera and hosts touring musicals and dance, the BBC National Orchestra of Wales is based in the city, and the music college stages frequent student concerts and plays. Small venues around Womanby Street put on bands most nights.

Saint-Malo's cultural life comes in bursts. La Route du Rock, Étonnants Voyageurs and Quai des Bulles bring festival crowds, but outside those dates the theatre's modest season and the odd cathedral concert are all there is.

Saint-Malo is a classic French thalassotherapy town. The seafront centre on the Sillon beach has heated seawater pools and hydrotherapy, and out of season, quiet walks on the empty sand followed by the pools make a real rest. August is crowded, so go another time if calm is the point.

Cardiff has no bathing culture to match. You are limited to hotel spas and pools at Cardiff Bay, so relaxing there means a slow morning in a Pontcanna café or a stroll through Bute Park.