As a hobby this year I'm beginning to experiment with mechanical computer designs, implemented in Lego Technics (yes, really). That's going to involve looking back to Turing machines, Babbage's difference engine, the Pascaline, and various other contraptions. I guess you could consider the means of encoding instructions for such machines to be programming languages, albeit very primitive ones.

Here's a couple of machines that others have built:

https://www.youtube.com/watch?v=FTSAiF9AHN4

https://www.youtube.com/watch?v=i_u3hpYMySk