Mr. Dekany, in Beneath the Hill had his own dig-it-yourself little coal mine, but he understood the fascination that holes in hills have for dogs and children, so,
"At a point about six feet into the hill, Mr. Dekany had closed the passage by fastening a heavy fence gate between the two stout old wooden supports to a heavy overhead beam. Beyond the gate the children could dimly make out a heavy pick and broad shovel leaning against a wheelbarrow. Opposite the wheelbarrow was a heavy wooden bin full of coal. Farther on was nothing but damp blackness...."
But Mrs. Dekany had been at her kitchen window when the children came out again, so the next weekend Mr. D., knowing that the gate was see-through and tempting, rounded up some boards and hinges and a padlock, and cut an old door down to size to shut the outer entrance, too.
Holes in hills are fascinating. When I was ten or eleven and on my way to school, not far from the bottom of the path I took down through the woods to State Street, there was an eight or ten-inch high opening under a stone ledge into what my imagination liked to think could be a cavern full of wonders. However, my common sense told me first that I'd better bring a flashlight and take a look inside before I tried to wriggle in. Secondly, it told me that I was too large, but the sandstone at the sides looked crumbly enough to carve wider with a soup spoon or a trowel. "Crumbly" was the word that made me flinch. I could just see the half of me that was skirt, panties, legs, socks and oxfords flailing in the autumn sunshine and slowly twitching into stillness as the hill clamped/ crumbled-- onto my top half. So I never even brought that flashlight down for a look. But I do remember the fascination...