Many Montessori materials, at least here in the US, include 3D realistic depictions of objects of interest going from famous buildings and landmarks to means of transport to wildlife. It is a bit challenging (not to mention expensive or prohibitive) to reproduce that at home, but I have found this website has a nice alternative: print your own 3D (scaled!) models and build them at home. All you need is a color printer, some paper and a pair of scissors and glue. OK, and lots of patience, but it is really a great project to "illustrate" any lesson.
Here is the link: 3D paper models
Check out some examples:
We are currently working on this one: