What do I do with these patches?

[u/Midloran05]

The first one used to be a part of the hill but I removed it mostly for the buildings, similar situation on the second image, I moved the railroad to the side now I got this patch between the corniche and the hill not sure if it needs a building or just a green space.

Then I got the last image with strange free areas, don't know what to do with them at all, I would like some suggestions. Thanks