While we were in Helsinki earlier this year we took an afternoon and visited Suomenlinna, a small group of islands just off the coast of Helsinki that are well positioned to defend the city and had been used throughout the centuries as a military  outpost and first line of defence against enemies. Nowadays no-body is fighting so Suomenlinna has become a popular day-trip destination for leisurely outdoor activities like picnics and (for the brave) icy dips in the sea.