So I just recently moved and build a 4x4 enclosure for my Russian tortoise (I know, size is too small, anything bigger would have not fit in my room though). I also put my eastern box turtle into my Russian tortoises old 5x2 enclosure. Here is my Russian tortoises enclosure
What is not visible in the picture is that my snake cage is on top of the tortoise cage, so I can't do a second level. Otherwise I would have made her one