Sofia city known for varied architectural styles of buildings, there are a variety of ancient architectural buildings since the Middle Ages, is one of the leading church of st. george, Serdica Amphitheatre and the Boyana Church which holds the largest museum collections of Bulgaria, these are combined such diverse Christian roman architecture, Neoclassicism , ancient roman, etc.. Located on the Balkans Peninsula, Sofia is a beta world city by GaWC rankings and is the 12th largest city in the European Union, is known as a global city which became one of the most important cities in Eastern Europe.