Helsinki

A magnificent 18th-century sea fortress spread across a cluster of islands, a UNESCO site and Helsinki's must-see — ramparts, tunnels, cannons and cobbled lanes, with grassy shores, cafés, museums and a submarine, all a short, cheap ferry ride from the market square. A wonderful half or full day: picnic on the walls, explore the fortifications, and enjoy the sea views back to the city. Beautiful in every season.

The gleaming neoclassical heart of the city — the dazzling white Lutheran Cathedral rising on its steps above a grand cobbled square ringed by pale, elegant buildings, the very image of Helsinki. Climb the steps for the view, admire the harmonious 19th-century architecture, and soak up the calm, stately centre. The city's most iconic sight, and the starting point for exploring the old town around it.

An extraordinary modernist church carved directly into solid bedrock, its circular interior lit by a ring of skylights beneath a great copper dome, with bare rock walls that give superb acoustics. Serene, unusual and quietly beautiful — a masterpiece of 1960s Finnish architecture and one of the city's most striking sights; time a visit for a concert if you can, to hear the remarkable sound. A small, unforgettable marvel.

The lively waterfront market square (Kauppatori) at the head of the harbour — stalls of berries, produce, crafts and Finnish snacks, food tents serving fried vendace and salmon soup, and the boats to Suomenlinna and the islands leaving from the quay. A bustling, seaside heart of the city and a great spot to eat and people-watch; grab a coffee and a cinnamon bun, and watch the harbour life. The salty centre of Helsinki.

Sauna is the soul of Finnish life, and Helsinki has some wonderful public ones — the design-forward Löyly on the seafront, the historic wood-fired Kotiharju in Kallio, or the Allas pool by the market. Sweat it out, then plunge into the icy Baltic (or a cold pool) and repeat; it's cleansing, communal and utterly Finnish. An essential, blissful experience whatever the season — and never more so than in the depths of winter.

Helsinki is a UNESCO City of Design, and its Design District — a warren of streets around Punavuori — is where to feel it, packed with design and fashion boutiques, galleries, antique shops and studios, from Marimekko and Iittala to tiny independents. A lovely area to browse, shop for that perfect Finnish object, and admire the city's world-famous eye for clean, functional beauty. The stylish creative heart of Helsinki.

Not your average library — Oodi is a stunning, wave-roofed civic 'living room' opposite the parliament, a triumph of Finnish design and democracy, with a soaring top-floor reading room under an undulating white ceiling, plus workshops, studios and free spaces for all. Beautiful, welcoming and quintessentially Finnish in its faith in public good; wander in free, admire the architecture, and see how Helsinki treats its citizens. A modern icon.

A beautiful 19th-century covered market hall on the waterfront — a warm, wood-panelled temple of Finnish food, its stalls piled with reindeer, fish, cheese, berries, pastries and salmon soup, with cosy café counters to eat at. A lovely, atmospheric spot to graze and to buy edible souvenirs; try the salmon soup, the reindeer and the Karelian pastries, and shelter from the cold among the produce. A delicious slice of Helsinki life.

A striking abstract monument to Finland's greatest composer, Jean Sibelius — a shimmering cluster of over 600 steel pipes like a frozen wave or a great organ, set in a pretty seaside park in leafy Töölö. A popular, photogenic stop and a nod to the music at the heart of Finnish identity; combine it with a stroll along the bay and through the park. A pleasant, green corner of the cultured western city.

Helsinki has quietly become one of Europe's most exciting food cities — a New Nordic scene of foraged berries, mushrooms, reindeer, fish and rye, from Michelin-starred rooms to cosy bistros and the buzzing Hakaniemi and market halls. Try the classics too: creamy salmon soup, Karelian rye pasties, cinnamon 'korvapuusti' buns and a shot of salmiakki liquorice liqueur. Fresh, clean and inventive; a delicious surprise.

One of Europe's coolest art museums — an underground gallery of immersive, playful contemporary and digital art, whose curving skylights bubble up into a public square where children clamber over the domes. Innovative, fun and beautifully designed, in the heart of the centre; check what's on (the exhibitions are often blockbuster interactive shows), and enjoy the quirky square above. A brilliant, modern side of design-mad Helsinki.

The largest Orthodox cathedral in Western Europe — a magnificent red-brick, golden-domed church on a rocky rise on Katajanokka island, a legacy of Finland's century under Russian rule, with an opulent, icon-filled interior. A striking counterpoint to the white Lutheran cathedral across the harbour, and a great viewpoint over the city and sea; a short, worthwhile stop on the way to or from the Suomenlinna ferry.

The bohemian district of Kallio is where young, creative Helsinki lives and plays — cheap bars, vintage and second-hand shops, indie cafés and, in summer, the huge, beloved Cleaning Day flea markets and the buzzing terraces. A great area to browse, eat cheaply and feel the city's unpretentious, hipster side; the Hakaniemi market hall anchors it. The most affordable and lively neighbourhood in an otherwise pricey city.

Helsinki's nightlife is relaxed and characterful — craft-beer bars and cosy pubs in Kallio, cocktail spots and design bars in Punavuori, and in summer, terraces and the odd rooftop soaking up the long light. It gets going late and can be pricey (drinks especially), but the mood is friendly and unpretentious; join the locals for a beer, a band or a long midsummer night. Small but with real charm.

Helsinki sits at the edge of a vast archipelago, and getting out onto the water is a joy — ferries and water buses run to green recreation islands like Vallisaari and Lonna, with walking trails, cafés, saunas and swimming, and in summer, day trips further out. A lovely, quintessentially Finnish escape into nature minutes from the city; pack a picnic, hop a boat, and lose yourself among the pines and rocks and sea.