Not far from his office, eastwardly, where two streets met at an angle, was a small open space too limited to be called a square, even if its shape had not been a triangle.

Here, under the shade of two very sickly trees, surrounded by tall warehouses, were a couple of benches.

Peter sat here many evenings smoking his pipe.

Though these few square feet made perhaps the largest "open" within half a mile of his office, the angle was confined and dreary.

Hence it is obvious there must have been some attraction to Peter, since he was such a walker, to make him prefer spending his time there rather than in the parks not far distant The attraction was the children.
Only a few hundred feet away was one of the most densely crowded tenement districts of New York.