This opening is about 8 inches wide by 16 inches tall. You have to bend down on your knees to see through the opening. When you do you see that there is a huge rock supported on a stainless steel cross and that below the rock is a pool of water. To the person walking into the courtyard, from the vantage point of standing erect, the rock must appear to be floating over the water. I love this detail. The average pedestrian walking by would not notice this fascinating interior world of the courtyard. The play on public and private space is interesting - and that only the curious are rewarded a small, restricted vision of the private inner world of this house.