You probably can get in there if you call them up before hand and politely ask them if you may look around.
When I wanted to go to RMDI I called them a few months beforehand and asked them if it was alright if I looked around. I told them that I would be wearing a certified hardhat and steel toe boots. RMDI told me that I had to show up on a specific date and time. When I got there I filled out a waiver and was on my merry way. Any personal I saw I was very polite to and if asked what I was doing there I politely answered that I have permission and had filled out a waiver. I did not mention that I had a camera and no one seemed to notice.