WW1 trench, Pirkkola, Helsinki, Finland

First World War trench in base XXII:12 in [Krepost Sveaborg](https://en.wikipedia.org/wiki/Krepost_Sveaborg) land front defense line in Pirkkola, Helsinki, Finland. The base was built in 1915 - 1918. There are also concrete remains of later ski jumping hill structures. More info: * [Location in Google Maps](https://goo.gl/maps/4bYdTmCKiTPuTaRV6) * [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=112.1000013820) (only in finnish)