a friend saw this design and asked if I could make one.
https://www.etsy.com/au/listing/911908372/recycled-concrete-round-step-terrarium?gpla=1&gao=1&

The one she saw was decorated with little people and tiny cactus

It's 20cm diameter and the steps go close to the centre.

I printed with a raft, to make sure I didn't pick any filament from other prints on the white base, but it should print without if you have a clean enough plate.