In the 17th century, Leipzig was one of the major European city-centres of learning and culture in fields such as music, astronomy and optics. Leipzig played a significant role in the fall of communism in Eastern Germany, through events taken place in and around St. Nikolai Church. After the Reunification of Germany, Leipzig has undergone significant change with the restoration of historical buildings and the developement of a modern transport infrastructure. Some of the largest employers in the area (outside of manufacturing) include the various schools and universities in and around the Leipzig/Halle region. The University of Leipzig attracts millions of Euros of investment yearly and is in the middle of a massive construction and refurbishment to celebrate their 600th anniversary.