Kivisalmi sound is close to Kotka city center by the cost of the Gulf of Finland. It connects Keisarinsatama bay and Vasikkasaari harbour. The sound is between Hovinsaari islet and Kotkansaari islet that are the city center.
The sound was broader in earlier times but now it is canalized with banks and quays as sides. It is only 15 meters wide. The are three roadbridges and two railroad bridges crossing and the whole canal is about 150 meters long. The depth is 0,9 meter and the free height 4,3 meters.