A domus de janas is a type of cave that was made by people a long, long time ago. It is a very special type of cave that you can only find in a certain place called Sardinia, which is an island in the Mediterranean Sea.
The people who made these caves were called prehistoric people, which means they lived a very long time ago before we had computers and phones and all the cool things we have now. They didn't have houses like we do, so they made their homes in these caves.
Domus de janas caves are small and narrow, with rooms inside. They're made of stone, which is a type of rock that is often used for building things. The people who made these caves used special tools to carve the rock into the shapes they needed to make the rooms.
Inside the caves, there are sometimes pictures and carvings on the walls. These pictures and carvings are special because they are very old and were made by people who lived a long time ago. They used these pictures to tell stories and remember important events.
Nowadays, you can visit the domus de janas caves to see what they look like and how they were made. It's important to remember that they were made a very long time ago by people who lived very differently than we do now. But they're still an important part of our history and we can learn a lot from them.