For all the focus on hard math, we should also have a bank of historical mysteries and cyphers that we can throw models at. I know a few historians (like https://generativehistory.substack.com/) that have been using new models on old untranslated handwritten records.
How about Linear AI?
Fable solved the Cyphral Distich (a 370 year old cypher). Super cool way to use Claude https://www.vals.ai/blogs/fable-solves-cyphral-distich