Alright, kiddo, let me explain Cele Kula to you in a simple way. Cele Kula is a very old and famous tower located in the city of Nis in Serbia. It was built about 200 years ago by a Turkish ruler called Haji Mustafa Pasha.
Now, when you look at Cele Kula, it might look like a regular tower, but it's not! It is very special because it has tiny holes all over the walls, and that's what makes it unique. These holes were made so that sunlight can come inside and create beautiful patterns on the walls. It looks like there are thousands of stars on the walls when the sun shines through the holes.
In the old days, Cele Kula was used as a prison, and it was very famous for being a very strong and scary prison. People who were put there couldn't escape because of its strong walls. That's why it's also called the "Tower of Skulls," because there were stories that the prisoners were killed and their skulls were placed around the tower to scare other people who would come to visit.
But don't worry, Cele Kula is not a prison anymore! Today, it's a very popular tourist spot, and people from all over the world come to visit it. You can climb up to the top of the tower and enjoy the beautiful view of the city. And if you look closely, you might be able to see the tiny holes on the walls too!
So, that's Cele Kula for you in a nutshell, my little friend. It's a very old and special tower with tiny holes in the walls, and it used to be a scary prison, but now it's a cool tourist spot where you can enjoy a beautiful view of the city.