Situated in the old town of Toruń's city hall which houses the Museum District. An architect developed the idea that the town hall will remind calendar. The highest tower of the town hall would mean years, four corner towers four seasons, twelve great halls twelve months, fifty smaller rooms, which meant weeks of the year and three hundred sixty-five windows as days in the year, but here there was a problem. It is known that every four years, followed a leap year, which consisted of the 366 days. Selected so clever solution. Once every four years the city rented a bricklayer, who made an extra hole in one wall of the city hall, the number of windows to match the number of days in a year. After the end of the hole bricked for the next four years.