Figure 2 shows the kind of setup I use (with variations) for temporary residents or quarantined new additions. I have also used similar setups in apartments (with lights for heat and UV).
This is not racoon proof!
Sod and dirt and some rocks.
Shelter is flower pot with hole poked into it.
Enclosure is sorta self-cleaning. Is watered regularly and exposed to sunlight (which is the perfect sterilizer).
A bunch of (surviving) redworms live in the substrate to help waste disposal and provide entertainment for the turtle.
I have a cover made from 1-by-2s and screen that I can put on when I know I'll be home late, or when the weather is bad, so that not too many leaves fall in. (See on left of photograph.) I attach the corners of the cover to bricks to keep it from flying off in the wind, and to keep curious cats out.
At night, I take the turtle in, we have racoons.
Inhabitant shown is my male Chinese Box turtle (Cuora flavomarginata).