According to legend the fortress was built in the beginning of the 11th century within only three months.
Dubrovnik Republic found out that Venice is planning to build a fort on a small hill near Dubrovnik to gain control over the city and immediately started construction of their own. Fort was finished within three month period so when Venice ship arrived they could only turn round and go back home.
Interesting fact from the past
Interesting fact related to fortress is that the walls facing the sea are up to 12 meters wide and ones facing the city are only 60cm wide. That is explained by fact that the captain of the fortress was always a foreigner and as a precaution Dubrovnik Republic built thin walls facing the city so they could break through them if a captain showed a sign of disobedience.