LoL at the wooden door, ours too. It is a homemade one as well.
Ours was built in the late 40’s or early 50’s, concrete, with air vents (mushroom shaped) that go to a small flower garden above and behind the house. You access it through a hatch in the floor of the back ‘mud room’, go down a steep flight of stares, through the door, and there is the ‘living room’ with chairs and shelving, then through another door to the east side, to the other room with bunk beds in it.
We have thought about turning it into a wine cellar.
Might be wise to keep it stocked with survival gear/food. We used to own a house also with a bomb shelter. It was a very sophisticated one with air pumps, etc. Entry behind library shelves. Nobody knew.