Maretarium is Finland's only inland aquarium dedicated to native freshwater and Baltic species — a uniquely Finnish institution where you can watch salmon, pike, perch, and Baltic seal in immersive naturalistic tanks.
What to expect
The centrepiece is a dramatic walk-through underwater tunnel where large Baltic and freshwater fish move silently above and around you. Themed tanks recreate different river and coastal habitats — from the rushing Kymi River rapids to the open sea — with expert multilingual signage throughout. The resident Baltic ringed seals are a particular highlight, especially during scheduled feeding sessions. The experience is calm, cool, and endlessly photogenic.
Good to know
Located in Kantasatama, directly at the harbour — no transfer required. Open daily in summer. Allow 1–1.5 hours. Check the maretarium.fi website for feeding times to plan your visit around the seal demonstration.
Sail there
Luxury cruises that call at Kotka — book through us, the fare is identical and your concierge stays on your side.