Secret Room

We found a secret room in our new house.

We were prying off plywood from the basement walls so the concrete contractor would be able to get a good connection to the exterior walls. Chunlin noticed a discrepency between two rooms in the basement. When we pried off the plywood sheet on the short room, a door was revealed. The original door from 1936, perhaps? Or from the 1950s expansion? It was in the older part of the house. What could be behind it?

The door had been nailed shut, but we are good at prying. We got one side's nails out and I slipped through into the secret room. . .