Warsaw, Europe's youngest capital, is a city with a long history. Already in the 10th century, in the region of today's right-bank Bródno district existed a fortified-town complex. In the centuries that followed, the settlements of Kamion, Targowe Wielkie and Solec developed. The latter was protected by a fortified castle town known as Jazdów and situated on the site of today's Botanical Gardens. Destroyed by invading Lithuanian Jadvingian barbarians, it was rebuilt at a different, more defensible site. Bolesław II, the Duke of Masovia, probably chose the site because of its tall escarpment and superior water supply from the Rivers Drna and Bełczącej (now the East-West Thoroughfare).