Donau-Theiß-Kanal

Danube–Tisa–Danube Canal (DTD) (Serbian: Канал Дунав-Тиса-Дунав, romanized: Kanal Dunav-Tisa-Dunav) is a canal system in Serbia. It is a unique hydro-engineering system for flood control and hydrotechnical management, amelioration, forestry, water supply, waste water evacuation, navigation, tourism, fishing, hunting.

Source: Wikipedia https://en.wikipedia.org/wiki/Danube–Tisa–Danube_Canal