R-9
Built in 1741 by the Austrians. In 1745, it was converted by the Prussians into the lunette-shaped water fort. In the 1807, the fort was destroyed by the army of Württemberg. Its reconstruction took place under the supervision of Cpt. Eng. Schultz II in 1809. In the years 1878-1880, it was converted into the single-rampart infantry and artillery fort. Since 1910, it was used as an ammunition warehouse. In the 21st century, it was subject to general renovation and became a great tourist attractionand a venue of cultural events.