Pirin forms the water divide between the basins of the rivers Struma and Mesta. These dives in Turkey were chronicled on the HBO documentary "Struma". British authorities in Palestine interviewed Stoliar about the "Struma" sinking. Another British attack in the Struma Valley was more successful. The motorway is named after the Struma River. The latter preferred to keep all of Macedonia as far as the Struma. On 17 August the Chegan and Struma offensives began. In 807 Bulgarian forces defeated the Byzantine army in the Struma valley. Israeli politics still refers to the "Struma" disaster. The Struma and the Maritsa are two major rivers in the south. Many of these ships sank or were caught, such as the "Patria", "Struma" and . Dupnitsa-Kyustendil expressway branching off from Struma motorway is planned to connect with North Macedonia. Kyustendil has a continental climate with Mediterranean influence (mostly along the Struma river). The other Bulgarian rivers flowing directly to the Aegean are the Struma and the Mesta. In 2018 the former Lyulin motorway was merged with the Struma motorway.