Pick the corner with escape routes in mind
Choose a spot your dog already favours if you can, because redirecting an established digging habit works better when the legal pit sits near where he naturally wants to dig. Keep it away from fence lines, since a pit beside a boundary teaches enthusiastic excavation exactly where a tunnel out becomes possible, and keep it clear of prized planting, utility markers, and any ground where weed treatments or fertilisers have been used. Partial shade helps, because a dog digging to cool down will work harder in a baked, sun-exposed patch, and a shaded pit gives him the cool earth he is seeking without the sunburn risk of a bare belly on hot ground.
Build it deep, loose, and clearly defined
Mark the pit generously, at least wide enough for your dog to turn around inside it, and dig out or build up a depth of loose fill he can genuinely excavate rather than scratch. Plain sand, a sand and topsoil mix, or loose soil all work; what matters is that it digs noticeably easier than the surrounding lawn, because dogs repeat the surface that rewards effort fastest. Frame the edges with timber sleepers, stone, or sturdy edging so the boundary between pit and garden reads clearly to both dog and humans, and rake out stones, roots, and any buried debris before the first session.
Teach the pit in the first week
Bury two or three favourite toys and a few treats just under the surface while your dog watches, then let him discover them, because early jackpots are what convert a sand patch into his preferred dig site. Praise digging in the pit warmly and by name. When he starts a hole anywhere else, interrupt without scolding, lead him to the pit, scratch the surface yourself to restart the game, and praise the switch. Most determined diggers, including terriers bred for exactly this work, transfer within a couple of weeks if the pit keeps paying and the rest of the garden stops being interesting by comparison.
Keep it safe, fresh, and worth returning to
Rake the pit over regularly, top up the fill as it compacts or migrates, and remove anything sharp or rotten that surfaces. Slightly damp sand digs better and flies less, so a light watering in dry weather keeps it inviting. If neighbourhood cats start using it as a litter tray, cover it overnight with a breathable sheet. Rotate the buried toys so discovery never becomes predictable, and put that small rotation job, along with the weekly rake-over, into KinsLe Care Teams, where a named family member can be assigned the pit and each finished refresh is marked with a timestamp.