This is the loci method, but I think they are more popularly known as “memory palaces.”
Some people will create memory palaces via their imagination, or, they could simply use the places they are already familiar and imagine walking through these places and associating the things you see along the way with the material you’re trying to learn or memorize.
This is actually something that I’ve used a handful of times in my studies and it’s pretty helpful once you get the hang of it.
