Imagine you are building a big wall to keep bad guys out of your house. Now, imagine you want to make sure you can see the bad guys coming so you can stop them before they get close. To help you do this, you decide to build special parts on top of the wall called turrets.
A turret is kind of like a small tower that sits on top of the wall. It is usually round or square and has little windows all around it, so you can look out and see what's happening. Turrets were really important because they helped people who were protecting the wall to see any enemies coming their way and to quickly sound the alarm to get help.
Now, Hadrian's wall is a very, very long wall that was built to keep bad guys out of one of the biggest empires in history, the Roman Empire. It was built a really long time ago, almost 2,000 years ago, in what is today England.
The people who built Hadrian's Wall were really smart, and they knew that turrets would be really helpful for defending the wall. So, they built lots of turrets all along the wall to make sure they could see any enemies trying to get in.
Each turret was built with stones, like big puzzle pieces, that were all carefully placed on top of each other to make a strong and sturdy tower. Inside the turret, there was enough room for a few soldiers to stand and look out at the surrounding area.
So, the next time you see a castle or big wall with little towers on top, you'll know they're called turrets and they were really important for keeping bad guys out!