This new homeowner – who goes by the handle oldsofthands – began his post on Reddit’s ‘What Is This Thing?‘ thread by writing: “House built in 1916 – on the other side of this wall is what used to be a “sewing room”, according to my landlord.”

Oldsofthands continued by saying that the house, which has eight bedrooms, was definitely decorated well for the time period it was built in. “I can enter the sewing room on the other side, and I’ve looked all around on the floor, where I believe the door would open up to… But can’t find the backside of the tiny door! It’s painted over, and feels very secure – almost locked,” the user added.

“This house has a complex laundry chute system but this seems way too small to be a part of it. This room clearly was built as a bedroom, as there is a bathroom and a closet, neither of which are near this bizarre little architectural feature,” the post concluded.

Oldsofthands noted that the clog pictured next to the door was a women’s US size 9 for scale.

Naturally, many people in the comments section underneath the post each had their own thoughts.

One person suggested the original poster cut through the door to see if anything was behind it, writing: “Get yourself a razor blade and carefully cut the paint and see if you can’t get the door free I wonder if it’s like a hole to the basement so you could drop stuff in?”

Someone else wrote that it could be pet-related, adding: “A cat door? Last time I was house hunting, one of the houses had cat doors to all interior rooms.”

A further user said that the door could have been used to conceal a gas valve, commenting: “House could have has gas lighting in its early years. That could have been use to hide a valve to shut the gas off to a room or section of the home. The lights themselves would have had little valves on them.”

In the end, one person had the correct response, chiming in with: “My 1924 home has a somewhat larger door (maybe twice the size of the one in the photo) outside the bathroom ‘looking in’ if you will. It provides access to what would have been the original bathtub plumbing but, due to remodeling over the years, now just looks into the area at the end of the tub without giving access to anything that actually requires access.”