Is this a prayer room or just a hidden room?

I inherited my house from my grandfather. When I divorced my husband, I was awarded it because it was important to me (that and my ex was a real jerk and I won full custody of the children). I have always wondered about this room that's in the house and what it was used for. It literally is a hidden room. If you were to walk around the house you wouldn't even see it, and it doesn't have windows either. The entrance is hidden in the back and on the side of our very narrow broom closet. Why it has double doors I don't know, but it does. It's carpeted and in one section has linoleum. I currently use it for storage because I already filled up the attic (I kept my children's clothing and other sentiments) and I don't want to have to move anything down to the second or third levels of the house. What in the world is this for? If anyone knows, PLEASE let me know! I also thought it could have been used as a prayer room or something. You can't be disturbed in there.