In Alkaseem (Saudi Arabia) sometimes I and my older sister went out for a walk. But we had a fear that we may get lost and will never make to come back home. So, we always follow a simple straight road, following the boundary wall of our clinic and walk to the end of that road. Then a big open space. As it's a desert area, the road and that open area were fully covered with sands. There were many other roads that also come and end at that open space. At the end of the open space, there was a small black door. We use to come to that open space and watch people. Never get the courage to pick one road and go ahead.
But the most interesting thing was that door. We have seen all people who walk and come to that area go inside that door. Then missing. Never seen anyone come from that door, like a black hole. You have to understand you are watching Alkaseen with a small girl's eye. We, the sisters discussed, what could happen here. But couldn't find a solution.
Later, we got a chance to solve that misty. A Saudi family invited us. We went there with other people by walking through that door. It's was a small corridor to go to another open space. Kind of a shortcut. But, because of the shadow, it looked like a black door.