A large complex of fortifications, also located in Estonia and Finland, was built before and during World War I as part of the system protecting St Petersburg, the capital of the Russian empire, from attacks by sea.
Suur kindlusehitiste kompleks, mis hõlmas nii Eestit kui ka Soomet, ehitati Esimese maailmasõja eel ja ajal osana Vene impeeriumi pealinna Peterburi mere poolt kaitsmise süsteemist