Turnu Fortress, Medieval fortress near Turnu Măgurele, Romania

Turnu Fortress is a medieval fortification near Turnu Măgurele featuring a central tower with surrounding defensive walls and a deep ditch. The structure is positioned strategically near the meeting point of two rivers and displays typical features of river defense works from that period.

The fortress was built in the late 14th century under Mircea cel Bătrân's rule as a critical defense point against Ottoman expansion. It functioned as part of a larger defensive network that monitored and controlled several river crossings.

The fortress was a customs point where raw materials, farm produce and craft goods were traded. Two medieval trade routes from Sibiu and Brașov crossed the Carpathians and followed the Danube here toward Nicopolis. In the 17th century Turnu was held by a member of the sultan's family.

The fortress lies 3 km south of Turnu Măgurele and 1 km from the Sâi–Danube confluence, on marshy ground where the water table sits close to the surface. Restoration and consolidation began in October 2018 and are ongoing, so parts of the walls may be closed off. The wet terrain makes the ground muddy after rain; sturdy footwear helps.

The fortress was part of a linked defense system with other fortifications at Giurgiu, Turtucaia, and Brăila that collectively monitored river boundaries. This arrangement reveals how medieval military planners coordinated distant points.