https://ciechanow.ski/mechanical-watch/

This website is incredible if you are the type of person who LOVES knowing how things work. The link I posted is to his mechanical watch post, but go to his archive and look through his other content. Every topic is filled with a series of interactive elements that REALLY shows you how something works. I think his internal combustion engine post is awesome as well. If you like this kind of thing and want to support it, he has a patreon too.