Gyms on the map: over 3100 fitness centres in Finland, from chains to municipal halls, by municipality. Free, no login and no paywall.
3 122 places in
The map shows 7 gyms in Maarianhamina - Mariehamn. This is the number of places in this service, not an official total for the municipality.
Avancian pieni kuntosali is right in the city centre. The farthest is about 3 km away.
Backebergs utegym, Baltichallens utegym. These have their own description, a photo or a Wikipedia article, so the place page offers background beyond the location alone.
On the place's own page. 5 places in Maarianhamina - Mariehamn have a link to their own website and 2 have a phone number. The most up-to-date information is always on the place's own site.