Mini Maraton Koper — Aquapark Žusterna

Beneath the surface, the water of the Gulf of Trieste holds remnants of a 16th-century engineering feat: a submerged network of wooden pipes that once channeled fresh water to the island city of Koper from springs two miles away. Swimming through these quiet coastal depths, one occasionally catches the silhouette of the 14th-century cathedral bell tower, which has stood as a beacon for mariners since its original bell was cast in 1333. This is the setting for the Mini Maraton Koper, an annual open water gathering held at the Aquapark Žusterna, where the history of the Adriatic meets the rhythm of a modern race.

Race day logistics

Organized by the Slovenian Swimming Association, this event on September 12, 2026, draws participants to the coastal waters of the Obalno-kraška region. The competition environment is shaped by the unique geography of the area, most notably the shell dune of Ankaran. Located between Koper and the border, this massive deposit of calcareous mollusc shells was created after 1990 as a byproduct of the Port of Koper’s expansion, forming the only structure of its kind in the country. Swimmers here are navigating a landscape defined by both ancient maritime infrastructure and recent industrial evolution.

Historical echoes

Koper’s identity is steeped in long-standing lore, from its ancient name Aegida—linked by myth to the shield of the goddess Athena—to the symbolic arrival of Bishop Nazarius in 524 AD. The spirit of the local waters is perhaps best captured by the legacy of Spartaco Schergat, a Koper native and WWII military frogman who earned the Italian Gold Medal for his daring operations against naval targets. For those seeking varied challenges in the region, the calendar offers different rhythms, such as the 16th Biserov Maraton Portorož, which takes place a week earlier on September 6, or the nearby Trieste 2026 event scheduled shortly after on September 19, allowing swimmers to experience the diverse currents of the upper Adriatic in a single month.