Ask HN: Areas outside of software conducive to hacking?

Like a lot of others on here I have for a long time enjoyed tinkering around and building little software projects. Recently, I've been building my own 8-bit computer from TTL logic by following Ben Eater's excellent tutorial [1]; it seems like electronics is another place with a lot of scope to tinker around and have fun solving little puzzles. This got me wondering - what other areas outside of software and electronics are conducive to this kind of tinkering, and what are the best on-ramps and resources to get into them?

[1] https://www.youtube.com/watch?v=HyznrdDSSGM&list=PLowKtXNTBypGqImE405J2565dvjafglHU