Ours had three trapdoors, one under the front staircase into a crawl space. House legend tells that it was used in the Underground Railroad. I don't see any practical use for a trapdoor over a cellar that had no utilities when built?
The second trapdoor was under the rear staircase and led to the cellar. I wish that one was still there, but it was closed off when the original oil furnace was installed to provide a path for ductwork to the back wing. Now we have to go outside to go to the cellar! Since the trapdoor ran at right angles to the floor joists, the framing is rather...interesting...in that area.
The third trapdoor was in the kitchen and went into the root cellar, which was at the front of the cellar. Since it was right in the walkway, the location was terrible (yes, let's open a gaping hole in the kitchen floor, right in the main walkway) I don't regret covering this one. But the framing alterations made to accomodate it were baffling to say the least!