Think of concentric squares, the refrigerator will be the underground den, the ref. will actually be on top of the ground but burmed all around 2 feet thick. The next layer where the tunnels will end in will be an above ground night preditor proof covered room, then through a regular size people door (open during the day closed at night) will be the ground run. The outside perimeter of the run on the rabbit side of the fence will have a short wall w/ planting space between the wall and fence for more forage.