Originally Posted by Thalassa

Here are a few outside of city centre:

Tarvaspää: the studio of Akseli Gallen-Kallela with some of his works and changing exhibitions (10 km outside of city centre in Espoo). Smallish but well worth the visit.

EMMA (Espoo Museum of Modern Art): in Tapiola, the largest modern art museum in Finland. Possibly a stronger permanent collection than Kiasma, the changing exhibitions vary greatly in quality. The building is a 1950 printing facility, quite spectacular. The same building houses some ethnographic collections, a watch museum etc. 10 km from Helsinki Centre, an easy bus ride.

Hviträsk: the studio of architects Saarinen, Lindgren, and Gesellius. A fantastic example of Finnish art deco building, with great insights into the life of Eero Saarinen. Spectacular location on a hilltop over some lakes. Roughly 30 km from city centre, easiest seen with a car.

Didrichsen Museum: a small, private museum just outside of city centre (in Kuusisaari). Lovely 1950's modern house with a small but high quality modern art collection and interesting changing exhibitions.

Villa Gyllenberg: a private museum close to Didrichsen with one of the largest collections of Schjerfbeck paintings around. Very limited hours (Wednesday 16-20, Sunday 12-16).

Seurasaari Outdoor Museum: the traditional Finnish way of life is displayed in the cottages, farmsteads and manors of the past four centuries that have been relocated from all around Finland. Five kilometers outside of the city centre, near Meilahti.

Tamminiemi: the official residence and now museum of Urho Kekkonen, the president of Finland from 1956 until 1981. Very close to Seurasaari.

Nuuksio National Park: pristine wilderness with plenty of hiking opportunities and spectacular views just 30 km from the city centre.

Cheers,
T.