Helsinki or Reykjavik?

Neither city is a beach destination, but Helsinki at least has a swimming summer. Hietaniemi's sand and island beaches such as Pihlajasaari fill up on warm July days, when the Baltic is mild enough to swim in for a few weeks.

In Reykjavik the North Atlantic stays too cold for more than a quick plunge, and the shore is mostly rock and black sand. The geothermally warmed cove at Nauthólsvík is the novelty, and the heated outdoor pools are where people actually swim.

Both kitchens are Nordic and seasonal, but Helsinki has more depth. There is salmon soup, Baltic herring and Karelian pies, the Old Market Hall, and harbour stalls selling berries and chanterelles in late summer. Add a modern Nordic tier and a serious coffee culture, and there is more to work through.

Reykjavik's ingredients are superb, from langoustine and Arctic char to free-range lamb and skyr, but the choice thins quickly beyond Laugavegur and the Old Harbour. Lamb soup and a harbour-side hot dog are the honest highlights, and the prices push many visitors to cook for themselves.

This is one of the widest gaps between the two cities. Helsinki tells a full architectural story, from Engel's Senate Square and Uspenski Cathedral through the Jugend streets of Katajanokka and Eira to Finlandia Hall and the Temppeliaukio rock church. Suomenlinna adds a UNESCO-listed sea fortress, and the Ateneum holds the national art collection.

Reykjavik has Hallgrímskirkja, Harpa and a handful of small museums, of which the Settlement Exhibition around its Viking-age longhouse stays with you longest. A day covers them all, and most visitors treat the city as a base rather than a sight.

The two are close, and the difference is in how a night out works. Helsinki spreads it across districts: unpretentious bars and karaoke in Kallio, cocktail bars and a few serious clubs in the centre, and waterside terraces that stretch summer evenings.

Reykjavik packs everything into a few blocks and two nights. On Fridays and Saturdays the runtur moves along Laugavegur through small bars that become dance floors after midnight, and in midsummer you walk out into daylight at 3am. Weeknights are quiet and drinks are expensive in both cities.

Here Reykjavik is in another league. Within a couple of hours are the rift valley at Þingvellir, the Strokkur geyser, Gullfoss, the south-coast waterfalls and a glacier tongue for ice walks. Reykjanes, close to the airport, adds lava fields and steaming mud pools, and winter brings ice caves and trips to look for the northern lights.

Helsinki's outdoors is gentler: skerries to kayak among, ferries out to picnic islands, the Central Park forest belt and Nuuksio's lakes and pine trails under an hour away. It is flat, easy and lovely, but it adds to a city trip rather than being the reason for one.

Helsinki has proper towns within reach, and one of them is in another country: Tallinn's walled medieval old town is about two hours away by fast ferry. Porvoo's wooden riverside storehouses and Turku's castle and cathedral are the Finnish options, by bus and by train.

From Reykjavik, outings are drives through landscape, with the open-air parliament site at Þingvellir the one essential historic stop. Skálholt, Snorri Sturluson's Reykholt and the merchant houses of Eyrarbakki are pleasant pauses on the road rather than places to spend a day.

Both cities are safe and relaxed with children, but Helsinki gives them more to do. An amusement park on a hill, a zoo on its own island, the Heureka science centre and Suomenlinna's tunnels and ramparts are all close at hand, and even the dark winter afternoons have swimming halls and library play areas.

Reykjavik's great draw is its heated outdoor pools, where children splash in the snow, and Perlan's ice cave works well for older ones. The drawbacks are long coach days to reach the big sights and the even higher cost of feeding a family.

Helsinki is far easier to move around. Trams, a metro line, commuter trains and ferries to the islands all run on one ticket system, the airport is half an hour away by train, and you never need a car.

Reykjavik's centre is just as walkable, but beyond it there are only buses, which are reliable but not frequent. The airport is about three quarters of an hour away by coach, and the countryside most visitors come for needs a hire car or an organised tour.

Helsinki is the better place to shop, and its strength is Finnish design. Aalto glass, bold printed textiles, ceramics and modernist furniture fill the studios of the Design District, the Esplanadi carries the national brands, and Stockmann anchors the centre.

Shopping in Reykjavik is a short walk along Laugavegur and up Skólavörðustígur. A hand-knitted lopapeysa is the purchase worth making, along with lava-stone jewellery, fish-leather goods and local records. It fills an afternoon, not a trip.

Neither city is cheap, but Helsinki is clearly the gentler of the two. Meals, coffee and drinks cost well above the European norm, yet lunch menus, market food and fairly priced transport keep a budget workable.

Reykjavik is expensive on another scale. Simple guesthouses, plain meals, guided tours and car hire all cost a great deal. Supermarkets, self-catering and the cheap public pools help, but you have to budget for high prices from the start.

Helsinki has the deeper classical life. Two orchestras play at the Music Centre, the National Opera and Ballet stages a full season by Töölö Bay, and Sibelius's legacy carries real weight. There is also a rock and metal club circuit, and the Helsinki Festival at the end of summer.

Reykjavik's Harpa is a fine hall for the Iceland Symphony Orchestra, but the city's real character is alternative and electronic music, with local bands in central bars and Iceland Airwaves in late autumn. In both cities, most theatre is in the local language.

Both cities are outstanding places to relax in hot water, with Reykjavik just ahead. Helsinki's ritual is the sauna: old wood-heated public saunas in Kallio, harbour complexes where bathers dip in the Baltic between rounds, even in ice, and the 1920s Yrjönkatu swimming hall.

Reykjavik's ritual is the geothermal pool. Every neighbourhood has one, with hot tubs, a cold plunge and often a steam room, Vesturbæjarlaug and Laugardalslaug among them, and the Blue Lagoon lies on the way to the airport. In Helsinki you alternate between heat and cold, while in Reykjavik you take a long, sociable soak outdoors in any weather.