Erfurt is the largest city in Thuringia. The most important institutions are the Federal Labor Court, the University and the Fachhochschule Erfurt, as well as the Catholic Diocese of Erfurt, whose cathedral is the Erfurt Cathedral, which, in addition to the Krämerbrücke, is one of the main attractions of the city. In addition, the city has an almost three square kilometer-sized medieval town center with about 25 parish churches and numerous half-timbered houses and town houses.