Mouth of Secret Accusations @ Doge's Palace in Venice

Looks to me to be either in Veneziano (the local dialect), or in early standard Italian (which is actually Tuscan). It translates roughly as: "Secret denunciations against those who hide favors and offices or collude to hide the true income of them."

I think it's the Secret Itineraries Tour. You have to book ahead but it gets you into the Doge's Palace but first you tour the area across the Bridge of Sighs to see the prison area the one where Casanova was held centuries ago then you get to tour the Doge's Palace afterward. As you have a reservation, you get in ahead of everyone else in the line up.
We toured this in '06 and loved it and as we were a group of 10 and were there only 2 days ahead of our cruise it saved us a lot of time. Just two of us stayed afterward for 3 more days.
Jean

I think it refers to the use of the 'Mouth' - if you suspected someone was an enemy of the state, you could write a note, drop it in the Mouth and the Council of Ten would deal with it. My Italian's rusty and Latin almost non-existent, but I believe "Denontie secrete" means "secret accusations".

Michael's translation is good. It is definitely not Latin; I minored in that language in college.

Thank you all so much for the help. I sincerely appreciate it. I spent hours searching the web for a translation and found nothing. thank you.

I guess seven years of studying Italian is finally paying off. :-)