Interestingly, a lot of people like to put their memory palaces in a building of some sort, like a virtual museum. For me, I don’t really have much in the way of building memory palaces, but I’ll share some of my own memory spaces, in the order that they come to me.
The solar system (I have an insanely detailed memory of the solar system, right down to the orbital paths and details of the many moons, asteroids, and comets. I swear it’s almost eidetic, like my brain is running a computer model of it! I can easily have 100 distinct locations here, although normally I just use the planets, dwarf planets, and their large moons. This is almost my default memory palace.)
The periodic table (which, shockingly, I learned as a wall chart and it is stored as such in my memory. Nothing really visual, but I can recall all 118 elements on it and if needed, pull up more visual associations of all 118 that make sense for my brain. I don’t have them stored in a memory palace, but just as locations on this chart. If I see the chart in my head, it’s just black letters in boxes, like your periodic table in school.)
The house I grew up in (more specifically, my room). Tried this as a memory palace and since I have a model solar system hanging from the ceiling, you can guess what happened.
My old high school (however, it’s been a few years now, and I am forgetting a lot of the details of about half of it.)
My old college (awful, and I kind of suppressed it. I only remember one hallway and maybe there was a second and I’m not sure anymore. My classes weren’t far from the entrance. I got out as soon as I could.)
My old old college (really hard to visualize as there were many buildings, some of which I have never been in, or some only just once or twice. Also, furniture in the student center was moved around so much that I never had many concrete things to go off of.)
Locations on a circle (10 degrees, 20 degrees, 30 degrees, 40 degrees, 50 degrees, etc. until 360 degrees. This for some reason is very memorable for me.)
Maps (e.g. of the US, Europe, etc. Also highly memorable and I can replicate these from memory easily. I also have every country of the world memorized.)
The town I grew up in (well, part of it. I learned the structure of the parts we often drove through in the mid-2000s as a child and enough has changed to where I can’t recognize certain parts of it anymore - it feels foreign!)
My apartment building (before I was forced to move out of it. I’m surprised I can still recall large parts of it, but surely this will fade with time. I’ll probably rememorize this once I have a larger and more spacious apartment to work from.)
Part of the city where I went to college in (at least the street as I could see it)
A linking system with one of these, or my 100 images for the numbers 00-99. (00 - Swiss knife, 01 - acid, 02 - sun, 03 - sumo, 04 - sour, etc.)
I may create a 000-999 system for larger uses. I’m feeling ambitious this upcoming New Year and have considered expanding pi past the 239 I have now. Perhaps I could assign 3 digits to a location instead of 2.
Also, Major System > Dominic System. Most humans aren’t memorable for me. SC - Santa Claus… um… going down a chimney with a bag full of toys. GB - Great Britain and nothing else. OJ - Orange Juice… orange juicing… some orange juice. This is why I don’t use Dominic.