Cusco is a place in Peru where the ancient Inca people used to live a long, long time ago. It's kind of like a very old city, with lots of historical buildings and ruins that you can still visit today! People come from all over the world to see Cusco because it's such an important part of history. The Inca people built really cool buildings, like Machu Picchu, which is a big old city on top of a mountain. Even though the Inca people aren't around anymore, their buildings and culture still lives on in Cusco!