We were there Friday morning at 9am and it was great. By 10 it started getting crowded with tourists and various wedding parties. I'd go as soon add it opens. The light is really nice but you need a pretty good camera to get crisp photos in somewhat low light.
In my opinion having been there a few times I would say as soon as it opens unless there is an event happening. Alternatively during the day time in the week avoiding lunch time. We got married there on a mid week morning and it wasn't too busy.
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