To build this mid-century modern credenza, start by cutting the top, bottom, and side panels from three-quarter-inch walnut plywood using forty-five-degree mitred bevel cuts along the joining edges. Assemble the outer shell using waterproof wood glue and internal corner biscuit joints or pocket screws, clamping the box firmly until fully cured. Install a vertical interior divider panel four inches from the right side, cutting a seven-inch pass-through archway inside to allow your cat to move freely between rooms. Use a jigsaw to cut a matching seven-inch circular entrance through the exterior side wall, smoothing the cut edges with progressive two-hundred-and-twenty-grit sandpaper. Fasten four angled metal mounting plates to the bottom base panel, screwing in six-inch turned walnut tapered legs. Finish the wood surfaces with three coats of non-toxic, satin water-based clear finish, and mount two tambour or flat wood sliding doors along the front upper and lower routing channels for effortless maintenance access.