The Kaše Breakwater Protects the Old Port

Situated at the entrance to the Old Port of historical Dubrovnik, this massive stone breakwater has shielded the harbor from the waves for over five centuries. The terrace of the nearby St. John’s Fortress and the city walls offer an excellent view of Kaše and the Old Port—a sight that beautifully illustrates how, for centuries, the people of Dubrovnik successfully balanced maritime trade, city defense, and world-class architecture.

Why Dubrovnik Needed a Breakwater

The location of Dubrovnik’s Old Port posed a strategic challenge. Open to the southeast, the harbor was frequently battered by the powerful Jugo (sirocco)—a wind that whips up massive waves and makes docking incredibly difficult.

To address this, the Dubrovnik Major Council decided as early as July 26, 1347, to build a breakwater to protect the harbor. It was designed to span roughly 51 meters, stretching northeast from the tower that is now part of St. John’s Fortress.

While the decision was made in the 14th century, actual construction didn’t begin until 1484, with work wrapping up in 1487. From that point on, rocks have been periodically added to the structure to maintain its stability and protective function.

The Engineering Solution of a Dubrovnik Master Builder

The Kaše breakwater was built according to the designs of the renowned Dubrovnik builder Paskoje Miličević, one of the most important military and civil engineers of the Dubrovnik Republic.

The construction method was highly innovative for its time. Rather than traditional underwater masonry, the project utilized massive wooden crates, known in the local Dubrovnik dialect as kašete. These crates were lowered into the sea, filled with stones, and then bound together to form a stable stone barrier.

This is precisely where the name Kaše comes from—it is the plural of kašeta, the local term for the wooden crates that served as the structure’s foundation. Construction costs were enormous for the era, totaling around 5,700 ducats, which underscores just how vital protecting the harbor was for Dubrovnik’s maritime commerce.

Defending the City Harbor

A heavy chain used to run between the fortresses of St. John and St. Luke, closing off the harbor to keep out unwanted vessels. This chain was so strong it could easily snap a ship’s keel. It was removed in 1484 when the artificial island of the Kaše breakwater was constructed based on Paskoje Miličević’s blueprints. Building the breakwater not only shielded the port from rough seas and storms, but also reinforced the defense system of a harbor facing the constant threat of naval invasion.

Harbor Names and Historical Records

Interestingly, older records and nautical charts sometimes refer to Dubrovnik’s old harbor as Luka Kašun. On Italian maritime maps, it appears as Porto Cassone, which similarly references the wooden crates (*cassone*) used to build the breakwater.

Damage and Restoration

Throughout history, the Kaše breakwater has been damaged multiple times by powerful waves and natural disasters. Significant damage was recorded after the 1979 Montenegro earthquake, which impacted the wider southern Adriatic region.

Kaše suffered further damage during the Siege of Dubrovnik (1991–1992) when the city was subjected to heavy shelling. Today, as part of Dubrovnik’s Old Town historic complex, Kaše is protected as a UNESCO World Heritage site.