Frankfurt an der Oder is a city located in the eastern part of Germany, on the Oder River. It is the fifth-largest city in the state of Brandenburg and has a population of approximately 61, 000 people. The city is known for its historical sites, such as the Marienkirche, the oldest church in the city, and the Altstadt, the old town. Frankfurt an der Oder is also home to several universities, including the University of Frankfurt an der Oder, which was founded in 1991.