Biskupin is a special place in Poland where people used to live a long time ago, before we had cars and computers. About 2,500 years ago, a group of people decided to build a village there. This village was very special because it was built on a big lake and had very tall walls made out of dirt and wood. The walls were so tall that they protected the people inside from bad guys who might want to hurt them.
But the village didn't stay there forever. After a long time, the people who lived there decided to leave and go somewhere else. They left behind their homes, tools and even some of their food!
Many, many years later, some very smart people decided to look at the old village and see what it was like. They carefully dug into the ground and found all sorts of interesting things! They found old pots and pans, jewelry, weapons and even clothes that the people used to wear.
They learned so much by studying what they found in the ground that they were able to figure out a lot of things about the people who lived there. They learned about what they ate, how they made their tools, and how they used to live.
Today, people can visit Biskupin and walk around the old village. They can see the old walls and houses, and learn about the people who used to live there. It's like taking a trip back in time to see what life was like a long, long time ago.