On the class list next to the "Create a class"-button, there's a link called "Show archived"

After you click it your archived classes will show up along with your normal classes, but the archived classes will have a small "Archived"-marker on them

You can see here that an archived class is now showing, and the "Show archived"-link has changed to "Hide archived". if you click "Hide archived" the archived classes will be hidden again.

Did this answer your question?