Ruukinranta Trenches Traditional Cache

The Krepost Sveaborg was an Imperial Russian land and sea fortress constructed around Helsinki during First World War. The purpose of the fortress was to provide a secure naval base for the Russian Baltic fleet and to protect Helsinki and block routes to Saint Petersburg from a possible German invasion.

The central part of Krepost Sveaborg was the old fortress of Suomenlinna where the fortress headquarters were located. Due to technological advances in artillery the old fortress was no longer capable of providing a sufficient protection, and a new main defensive line was built well beyond the old fortress boundaries. New coastal artillery guns built on outlying islands protected Krepost Sveaborg from the sea, while fortified lines constructed around Helsinki were intended to stop any attacks on land.

The nearby caches Tulipesäke and Ruusutorpan maalinnoitus are also part of the fortress Krepost Sveaborg.