Mittenwalde is a town in the Dahme-Spreewald district, in Brandenburg, Germany. It is situated 30 km southeast of Berlin.
On May 28, 1562 the town of Mittenwalde lent Berlin 400 guilders. The debt has never been repaid, though the town has attempted to collect the debt on rare occasion. The amount in 2012 would be about 112 million euros, with simple interest. With compound interest the debt would be in the trillions of euros.