Treptow-Köpenick (pronounced [tʁɛptoː køːpɛnɪk], with a silent w) is the ninth borough of Berlin, Germany, formed in Berlin's 2001 administrative reform by merging the former boroughs of Treptow and Köpenick. Among Berlin's boroughs it is the largest by area with the lowest population density. The Johannisthal Air Field, Germany's first airfield, was located in Treptow-Köpenick, between Johannisthal and Adlershof. Treptower Park, a popular place for recreation and a tourist destination, is also located in the borough. The park features the sprawling Soviet War Memorial, a war memorial to the Soviet soldiers who fell in the Battle of Berlin in 1945.