Novi Sad, established in the 17th century, is Serbia's second largest city. Its diverse population of Serbs, Hungarians, Croats and Slovaks make the city a highly developed cultural and economic hub. The lively city center has museums, art galleries, and an eclectic cafe and bar scene. Architectural styles include Gothic, Baroque, Art Nouveau, and Neoclassicism. One of Novi Sad's most notable sights is Petrovaradin Fortress. The fortress sits on the right bank of river Danube and provides a home to art studios, a museum, and a hotel. The city is also home to the annual Exit festival, one of Europe's most popular music events.