The amusement park Linnanmäki is Finland’s most-visited attraction, and its spring opening is a major annual event on the calendar of Helsinki children.
As well as a selection of rides and attractions of varying degrees of scariness, Linnanmäki houses Sea Life, an excellent aquarium and marine education centre.
If you still have some energy left after a day at Linnanmäki, Tropicario, a tropical animal house is near by at Sturenkatu 27.
Another big Helsinki attraction for children takes us back to the sea and the island zoo of Korkeasaari which you can reach by ferry from the Market Square and from the square at Hakaniemi, as well as by footbridge from Kulosaari in eastern Helsinki.
Animals indigenous to the north, including elk, lynx and reindeer, are well represented, but there is a generous selection of exotica, such as camels, lions and snow leopards.
The Natural History Museum at Pohjoinen Rautatiekatu 13 is the third most popular museum in Finland.
You can stop at the feet of a dinosaur or listen to the sounds of wild African animals.
The Tram Museum (Töölönkatu 51 A) is located at the oldest tram depot in Helsinki.
The museum houses a smallish but interesting collection of trams, and there are also old uniforms and tram tickets on show.
You may step inside some of the old trams. Free entry.
There are several free playgrounds in central Helsinki.
The most centrally located playgrounds are quite small (for example, the ones at Vanha kirkkopuisto, Lönnrotinkatu 6 or Kaisaniemi park), but a few bus stops away from the centre you’ll find nice parks by the sea.
At Kaivopuisto park (Puistokatu 4) there is a biggish playground with a sea view.
The playground of Lahnalahti (Lauttasaarentie 40-42) is a gem: a playground next to a nice beach with a café.
Take the bus no. 65 A towards Lauttasaari and ask the driver for instructions.
If it should rain during your stay, try one of the indoor adventure parks.
The little ones can release their energy by running, bouncing, jumping and climbing.
Huimala (Ajomiehentie 1), a bit off the centre, is an exclusive indoor adventure park for the whole family, open all-year round.
Children can jump on trampolines or slide down the longest indoor slide in Finland, while older children and adults can ride thrilling zip-lines, step on the high ropes courses or climb the climbing walls up to almost 20 meters in height.
Most of the department stores and shopping centres have play areas and childcare facilities.
You can change diapers, heat up food and let the older kids play on the 6th floor at Stockmann, the 3rd floor of the Kamppi shopping centre or the newish 3rd floor of Forum shopping centre.
If you wish to shop for something original for your kids, try Punavuoren Peikko (Uudenmaankatu 15) or Harakanpesä (Eerikinkatu 12) for stylish Scandinavian clothes.
Ombrellino (Pohjoisesplanadi 17) is a tiny shop on a busy shopping street, brimming with wonderful toys.