The baby carrier in the foreground gives a clue. For in reality this scene was filled with people, adults and children walking and splashing through the water on this hot October late afternoon. I didn't Photoshop them away – I used a much older technique of removing people from a public place.
This was a very dark neutral density filter and a very long – 30 second – exposure of this scene. During that time people came and went, but lingered so briefly in any one spot that they became invisible to the camera. The blurring of the water of the fountains and of the tree leaves blown in the wind is tell-tale sign of this treatment.