About 200 km north of Warsaw, with the Vistula flowing gently alongside, stands the medieval walled city of Torun. Entering the city through the giant walls feels like stepping back in time. Especially since Torun is inextricably interwoven with the life of iconic mathematician and astronomer Copernicus. The castle is also a living testimony to the might of the Teutonic Knights, the mysterious German military-religious order that ruled over the area in during the 13th, 14th and 15th centuries and painstakingly built the town. Unfortunately, their most prominent structure, the castle, is just a series of ruined walls. There is also a leaning tower that stands testimony to the love between a knight and a local girl.