Cavtat Coastal Defence Tunnels Sustjepan

A Cold War Artillery Position on the Rat–Sustjepan Peninsula

Peter Swart

June 2026

Introduction

Near the tip of the Sustjepan Peninsula at Cavtat, Croatia, a largely forgotten military tunnel complex lies hidden beneath the limestone headland overlooking the entrance to Župa Bay and the sea approaches to Dubrovnik. Although well known to generations of locals and visitors, the site has received little formal documentation in English.

The complex consists of approximately 70 metres of interconnected concrete-lined tunnels, nine underground rooms, several gun positions, and an elevated observation post. The surviving structures appear to form part of a Second World War/Post WWII coastal defence system established by Italians and later used by Yugoslavia during the early years of the Cold War.

The tunnels occupy a strategically significant position. From the headland, artillery could command shipping approaching Cavtat while observers enjoyed extensive views across the Adriatic towards Dubrovnik and the offshore islands while remaining hidden.

Tunnel Layout

The tunnel system is arranged on several levels connected by stairways and a vertical shaft. The lowest entrance lies approximately 15 metres above sea level and leads into a straight tunnel running roughly south into the limestone bedrock. This passage is about 20 metres long and forms the principal access route into the complex.