We got the city pass and it pass for all of the stuff empire state building and statue of liberty and all that
Thursday thru Monday from 10-5 very little waiting they keep it paced
Sunday afternoon
Per the Groupon page (under inclusions), you're guaranteed to skip the lines.
The Groupon is for a separate, family run memorial museum. I believe they state this on the Groupon page. I don't believe it is applicable for the 9/11 museum on the premises of the world trade center.
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