Finngrundet used to be anchored in the ice free season in the Gulf of Bothia, but when automatic lighthouses began to replace lightships in the 1960s, it was retired and converted into a museum. To its left is part of Sweden's first icebreaker, the Sankt Erik. Built in 1915, it slides over the ice and crushes it and can also be rocked sideways to widen the channel. One of its two 3-cylinder engines is Sweden's largest working steam engine.