I almost forgot we bought these on our trip to Sweden last year. Instead of ice cubes, you freeze these Viking rocks! They actually have the word ‘Ice’ in Runic on them. Learn about runes here: https://en.wikipedia.org/wiki/Runes.
We had a fantastic time in Stockholm, I would be thrilled to go back one day. I’ll dig out some other pics but we bought these from the Viking Museum. Reminds me, I haven’t watched Vikings in ages. Skol!