I do not have any closed areas for my specifications, so instead, I decided to go for a bridge between platforms.
It occurs to me that I should have made a split up bridge. You know, an end piece and a middle piece, but maybe this is fine?
It is exactly 9 meters long and 5 meters wide, so it is a small bridge, but it fits my reference material’s scale nicely, without being too similar. I have 2 final models, one with grooves on the floor and one without.
It is quite detailed at the moment, in fact it’s 5664 verts. From testing, I can remove around 2000 verts using the decimate modifer, while it may remove some small details.
Edit:
Sorry, was in a hurry so I forgot some details. So, I made the bottom and rails using the methods we’d learned of curves for practice, by using a bezier curve. I started with just plain cubes, as adding details early on caused problems. I also used the mirror modifier and it was a godsend.
The large pillars don’t actually go through the rails. Rather, I extruded and created the top parts manually. So I went with sight as having parts not exactly the same scale or height felt more appropriate for a stone brick bridge. As far as I could see, nothing went into anything else, though I could have missed something.
Couldn’t have done this without the guidance, thank you 
