Leiderdorp is a town in the Netherlands that has experienced changes throughout history. In ancient times, villagers lived in huts and farmed livestock. In the Middle Ages, castles, monasteries and churches were built. Today, Leiderdorp has merged with the city of Leiden and has a population of around 26,446 living in an area of 12.29 square kilometers. The land was once quite marshy but avoided major flooding.