Fortress Ekrensko Kale (aka Ekrena) was located at hill near the present village of Kranevo. It was built on the site of an ancient Roman fortress. In the Middle Ages the fortress was very important for the protection of the country during the First and Second Bulgarian State.
After archaeological excavations made south of the village (at Frangensko plateau) were found ruins of a Roman fortress and settlement (II century) and also the ruins of Bulgarian defensive shaft which was included in the defense system covered the area between cape Kalikara (Kaliakra fortress) and cape Emona.