@Dutchy,
See, easy peasy.
I've been there, loved that garden, took a lot of photos I also love now, these years later. Don't remember this mosaic garden, hah! - just one part of an elaborate place. But I do recognize the pillars. This was designed by Beatrice Farrand, someone who is a sort of light to the eyes of female landscape architects re history.
There was a remodel of part of the garden not too many years ago that was controversial to those who follow such things - don't quite remember but I think it had to do with an underground facility and how it would or would not wreck the major lawn area.