WWI Fortification Lines
Trips last from 2-6 hours, rangeing from very easy to hard terrain.
When WWI broke out all around Helsinki a fortified terrestial defense line has been built by Russia in 1914-17. Its main purpose was to hinder a potential terestial attack of Germany from the mainland on the Russian fleet at Suomenlinna. Significant parts of the fortification line still exist even though building of houses and natural deterioration have taken their tolls. Decentralized defense system consist of trenches, firing positions, tunnel type shelters, batteries and military roads.