You could say that the whole Pihlajasaari is one big beach. The shallow sandy beach, close to the dock in northern part of the island, is perfect for families with children and those who prefer sandy beaches. The beach is about 500 meters long. There’s a kiosk and a playground for the children on the beach. Toilets and showers nearby.

The rest of the shore is quite rocky, but swimming is possible almost everywhere. On eastern (separate) island there’s a naturist beach.

There’re two sauna’s which are rented by the City of Helsinki
https://www.hel.fi/helsinki/en/culture/recreation/recreation/saunas/pihlajasaari