Suomenlinna is a must-visit when in Helsinki.

This historic sea fortress is spread across several islands just a short ferry ride from the city center. Built in the 18th century, it’s now a UNESCO World Heritage site, but what makes it special is the atmosphere, not the history lessons.

HOW TO GET THERE: You can reach Suomenlinna by a public ferry from Market Square (Kauppatori). The ferry is included in a normal public transport ticket and the ride takes about 15 minutes. It already feels like a mini escape from the city.

COST: The island itself is free to explore. The only cost is the ferry ticket (included in a normal public transport ticket).

Plan at least 2–4 hours for your visit, it’s bigger than it looks. My local tip: wear comfortable shoes and don’t try to see everything. The best moments usually happen when you walk off the main paths and just explore.

In my opinion, the best time to visit is summer, when the nature is super green, flowers are blooming, and you can swim and enjoy the sun. Autumn and winter are perfect if you want a quieter, more peaceful experience with fewer visitors.

THINGS TO DO:

• Wander around the fortress walls, especially The Blue Route, which runs through the islands from north to south and gives you some of the best views.

• Explore the tunnels and old fortifications scattered around the islands.

• Stop at one of the cafés for a coffee or lunch. Suomenlinna is a great place to slow down.

• Pack snacks and enjoy a picnic on the rocks by the sea, this is something locals love doing, especially in summer.

• Visit one of the museums if you’re interested in history. They’re optional, but a nice addition if you have extra time.

• Visit Submarine Vesikko, a former Finnish submarine that you can explore from the inside (open seasonally).