This is Dave, my lone Roborovskii's cage - I've grabbed some different views, so you can get an idea.
Dave is a very small, very nervous little Robo - tame, but not overly fond of the outside world. She likes some safe space, so I've made sure she has plenty.
Here's the bottom of the cage, showing the burrows I've made for her - the one on the left is simply a u-turn tunnel, but the one on the right leads to another nest, where I hide treats
Main shredded paper nest is top left.
Dave used to be quite keen on digging - "stereotyped behaviour", as I've since discovered - whereby she was digging, because her nature compelled her to do, in the absence of an existing burrow. I've had some amazing success putting these in , and the behaviour has disappeared!
View from the side - she has a wheel, and I've added a climbing frame the second level. She enjoys climbing on the bars, and has become stressed when I've previously tried to stop this. So the frame is there to facilitate this, safely, and there's plenty of bedding beneath.
View from the top - sandbath is in there. Not a massive cage, but she seems to enjoy it. All that's missing are the climbing treats I hang from the bars, which give her a way to climb down from without dropping.
And, lastly, a sleepy little Dave emerging from her burrow!