Sometimes Kalisz is called "the oldest town of Poland" because of mentioning by Ptolemy a town called Calisia that was situated on the Amber Trail.
... size is 2.47 and the average family size is 3.07. In the town the population is spread out with 22.3% under the age of 18, 6.7% from 18 to 24, 28.0% from 25 to 44, ...