It's shocking. A double-storey gunhouse warship named Vasa was built in 1628. The King envied Norwegian warships and ordered his own designers to build the same large gunboat within two years. When the designer died, the apprentice took over. He was not very skilled. He built an additional layer on the original gunboat design without calculating the weight. The new ship was launched, but after sailing more than a kilometer, it was overturned by the wind and sank to the bottom of the sea. After 400 years of silence, the Swedes paid a lot of money to salvage and build the Museum of the wrecked Vasa. The hull is very large and well restored. It's worth seeing.