A time capsule is a container filled with special items that you bury underground or seal in a hidden location for someone to find in the future. It is like a special message or gift that you can give to someone in the future. For example, you could put pictures, coins, stories, or other things inside the time capsule. Then, you can decide when you want someone to find your time capsule, like in thirty years, or even in a hundred years! When that time comes, someone can open the time capsule and see all the things you put inside.