This is a drum. Or a gong. Or maybe a throne. Or a model of the universe with little solar disks around the edge.
It was found in a bog near Balkåkra, Sweden, in 1847, but was made sometime during the Bronze Age, more than 3.500 years ago. It consists of 10 pieces of cast bronze held together by a riveted tin band. The only other object like it was found in Hungary, and there are signs it was made by the same craftsman. No one is sure what that one was made to do, either.
I found it in a Balkakra Ritual Object category on Wikimedia Commons.