Thank you so much! I poured so much time into that map, so I'm very happy to read this :D   I'd absolutely love to go over the creation process! I've actually even outlined it recently, as a part of the process of creating a portfolio for myself. It's a bit of a process, because I put a lot of pre-planning into the shape and layout of the city before even diving in to the part where I drew it! haha. I'll write out the entire thing here though! I used a "Mapgen4" for the base landmass, AutoCAD (just because I'm used to it) for planning the city portions, and then Krita at the end to bring it all together and draw it.   The images may all be a bit small here, but you can click on them for larger versions if you like!                         As for the layers that were the catacombs map and old russin map, I turned a new layer on in Krita and set it to 50% transparency, and then began drawing on top of everything! That way I could tell where things were and plan each piece out so it fit together. I saved them as separate images and uploaded each to World Anvil, which I then used as the different layers you can select on the map.       I think I covered everything, if not let me know! Hopefully I didn't go too overboard on things either, I get kinda carried away talking about this! haha.