The tower is a defensive structure at the end of Pikk tänav (Pikk Street). Together with the Suur Rannavärav (Great Coastal Gate), a sixteenth-century arch flanked by two towers, it served to defend the harbour of Tallinn. Later, it was used as a storehouse for gunpowder and weapons, and then transformed into a prison, and was the scene of an outbreak of violence during the 1917 Revolution, when the prison guards were murdered by a mob of workers, soldiers and sailors.