Hi from Ireland!
I decided to do a practice project for each section. That will give me more confidence with structure and perspective.
This is my wooden hut in a forest of giant mushrooms. They don't come across as well as I'd like, and the thumbnail is better than the final picture. Some of the reference photos I saw had these little porches sticking out over water and I loved them so I added one. I'm not sure whether it would be correct for an actual historical setting, but neither would giant mushrooms. Hopefully the structure at least makes sense.
The sticker was my inspiration for the mushrooms, so I stuck it in the sketchbook. (The building is drawn on paper that I dyed with avocado; that's why it's pink.) I screwed up the perspective a bit and had to put a gap at the end of the porch/pier to try to make it look deliberate, but for my first serious attempt at drawing something like this, I'm pretty happy with it.
Next, my medieval street. It's a bit basic and not very original, and I know I made the street too wide, but like with the house, this was the first time I really tried to do this properly, perspective and all.
The idea is that the forge is under the stairs, with the weapons shop right beside it so the blacksmith can sell his/her creations. There's a cart outside for advertising, but the items on it are duds, so it doesn't matter if they get stolen. The mapmakers' guild is housed above the shop. Across the street is the tailor/dressmaker, who lives above his/her own shop. The area used to be wealthy, hence the skillful signs and traces of glass in the upstairs window, but is now falling into decay. That's why there are cobblestones missing (they look more like flagstones, but they were supposed to be cobbles). I know the cat shadow is very cliche, but I like it anyway.
Here's my castle. I had trouble coming up with a concept and motivating myself to draw it, which is weird because I like castles.
Anyway, it's not that original in design, but it sits on a giant pillar of rock, surrounded by other smaller ones. It's out of reach of siege weapons, and it would take years to dig through the rock enough to undermine the castle. People and goods are brought up in a lift operated like the one on the Wall in GoT. It can be destroyed instantly if needed, as the structure is made of wood. For added security, they have a drawbridge and several towers. There's a well that reaches deep into the pillar to pull water up, like in Mad Max: Fury Road. They grow what vegetables they can high up and import meat.
Finally, my cathedral. I had trouble coming up with anything, because I looked at references and got overwhelmed by the detail. Eventually I decided to focus on one section and just start drawing, then add things later.
I imagine the story behind it is that it's a cathedral to the spirits of the four winds. This section is for the north wind, who's believed to be all seeing. Circles are sacred because they look like eyes. Panels and windows show stories of great deeds performed by the spirit. The figure near the top of the flying buttress is an image of the spirit, cloaked because no-one knows what it looks like.
I really enjoyed this course, thank you so much for creating it!