In 2014 we spent the day in Helsinki on a land and water tour.  I think they were pressed a little bit to find much to show us in the city to be honest.  The Church in the Rock was probably the highlight.  The second part of the day was on a tour boat of the harbor area and a lot more interesting. 

In 2024 we took a ferry to Suomenlinna Island to visit a 500 year old fortress complex.   The fort was built by Sweden at the time and remains the most expensive project they have ever had.     It is a very large complex and 800 people live on the island even though there has been no military presence there for a long time.