Yes, you do recognize this picture. Here it is again as a refresher. As you'll recall, the ground-level opening at the left is one of the two vents for the root cellar.
Below, a closer look. The shaft is about four or five feet long, angled steeply down. I don't know what they did to discourage little animals from sliding in. Maybe nothing.
The following photo is taken from inside the root cellar, looking steeply up the ventilation shaft. You can see the wrought-iron grate-thing in sillhouette at the far end; compare to the previous shot.
Inside the vaulted root cellar. Both ventilations shafts are visible. They're about six feet above floor level, making the top of the vault about nine feet.
The niche in the far wall and the "wainscot" look on the long walls are nice details for a utilitarian room like this.
Took this overview shot lying uncomfortably on my back on the damp but gorgeous rough-hewn stone steps leading to the old outside door.