They provide lockers for "the baby"
I skipped the art museum because I only wanted to see the large gold statue upstairs and the making of Parthenon. There is a small elevator. It costs to go inside but seeing the outside is free. The gift shop closed before I could go in. We took about 2 hours.
You can spend 20 minutes to a few hours. You go your own speed and see/read what you want.
One hour is enough.
I think you could see everything in about an hour
About an hour to an hour and a half.
Honestly I can't say because when I went it was closed so all I was able to do was take pictures from the outside
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