Cave entrance in WW1 base, Helsinki, Finland

Entrance to 20 m² cave in First World War base XI:2 in [Krepost Sveaborg](https://en.wikipedia.org/wiki/Krepost_Sveaborg) land front defense line in Ala-Malmi, Helsinki, Finland. The base was built in 1915 - 1918. The cave has acces to trenches in the hill above. This base build in the hill of Ormusmäki has rare combination of caves and trenches in the same hill. Caves are build under the trenches and there are entrances from threnches to the caves. The whole base contains 4 caves: 23 m², 85 m², 20 m² and 23 m². More info: * [Location in Google Maps](https://goo.gl/maps/tRFvMkRRfcoRaJ548) * [Wikipedia: Krepost Sveaborg](https://en.wikipedia.org/wiki/Krepost_Sveaborg) * [John Lagerstedt , Markku Saari: Krepost Sveaborg](http://www.novision.fi/viapori/eavaus.htm) * [Finnish Heritage Agency site info](https://www.kyppi.fi/to.aspx?id=112.1000013430) (only in finnish) Source: Objaverse 1.0 / Sketchfab