Visiting one of the most odd of all archipelago attractions and activities.
On Gålö in southern archipelago you can visit a Swedish top secret military experiment from the Cold War. Swedish military actally trained seals for marine actions.
You can stay at Gålö Sälstation in one of three selfcatered cabins, there are rowing boats, stand up panel boards, kayaks and beautiful walking paths. A brand new sauna by the water full fills the experience of Gålö. See http://www.salstationen.com/archipelago-hostel-stockholm/ for more pictures.