 The fortress' position connecting the Balkans and Central Europe has made it an important religious and commercial center for centuries, now aided by being on the Pan-European X corridor.The Danube also connects it to many other historic sites, most notably Belgrade and its suburb of Vinča, Novi Sad, Golubac Fortress, Lepenski Vir and Viminacium.Amidst the turbulence of the Ottoman conquest of the Balkans in the early 15th century, the region's Christian rulers lost several battles, such as the Battle of Kosovo and the siege of Veliko Tarnovo.