Placing wooden box underground; how to protect?
Use pressure-treated wood and coat the outside with asphalt emulsion (some call it bitumen). Remember- high &amp; dry, like on a hill. And if you bury anything above the frost line and leave it over winter, it will at least move and maybe break (climate depending). Pay careful attention to the lid closure to make it watertight, and add some sort of dessicant to combat condensation inside the box.