The treaty confirmed that the Finnish-Soviet border would follow the old border between the autonomous Grand Duchy of Finland and Imperial Russia. Finland additionally received Petsamo, with its ice-free harbour on the Arctic Ocean. As far back as 1864, Tsar Alexander II had promised to join Petsamo to Finland in exchange for a piece of the Karelian Isthmus. Finland also agreed to leave the joined and then occupied areas of Repola (joined to Finland during the Viena expedition) and Porajärvi (joined during the Aunus expedition) in Russian East Karelia. The treaty also included Finland handing over the contested region of North Ingria to Russia, thereby disbanding the short-lived Republic of North Ingria. The treaty also had some articles besides area and border issues, including Soviet guarantee of free navigation of merchant ships from the Finnish ports in Lake Ladoga (Laatokka in Finnish) to the Gulf of Finland via the River Neva. Finland guaranteed land transit from the Soviet Union to Norway via the Petsamo area. Also, Finland agreed to disarm the coastal fortress in Ino, opposite the Soviet city Kronstadt located on the island of Kotlin. The Finnish outer islands in the Gulf of Finland were demilitarized.