Security in a mint?

US or UK?

You can check out a Virtual Tour here: http://www.usmint.gov/mint_tours/index.cfm

I can tell you that in Washington, DC, you cannot tell it's a mint. It's just one of the buildings sandwiched in on 15th Street. Looks like all the other buildings. The only difference is that there's a line in front of it on the sidewalk during the summer -- but then there's a line of tourists for a building near it, too.

Haven't been it in years, but I can tell you it probably has security like the rest of DC--metal detectors and a guard to check through any bags you have.

I'm pretty sure that in the US coins are made in different locations from paper money. You can tell where the coins were minted by the letter on them: P for Philidelphia, D for Denver, and S for San Francisco (San Francisco has not put any coins into circulation since the 1980s. Paper money is not minted, it is printed. From what I remember of touring the Bureau of Engraving and Printing in Washington D.C., you can see some steps of the process through glass, not sure how thick the glass was. Also, uniformed security guards seemed pretty minimal, but I'm sure the security was extremely tight.
Hope that helps!

Oh, I forgot. One of the ways they keep staff from stealing money is by having a majority of the process done in sheets of notes (this is for paper money, not sure about mints). Only at the very end of the process is the money cut into individual bills in an extremely secure area that the public does not get to see. Then they would probably scan the bills to make sure all the printed serial numbers were there. It seems like it would be very simple to count the money that's printed and compare it to the number of bills they know they've printed.

They all have security cats. They are very observant and vicious. They feed them very little, just enough to keep them hungry. You do not want to mess with Security Cats.