Prov has some awesome gems. Here's a few. I wont tell you exactly where they are because most i dont remember, but if you recognize them, check em out.
We'll start with Bootleggers Nightclub.
This is prob the easiest Prov location, but it's also trashed. Prob the same building you mentioned Mista.V
Security here is almost non existent, unless you're being a loud douche. Easy as pie.
------------------------------------------------------
Colonial Knife Co.
Again, a real easy location, but again, kind of trashed. There is some really awesome graffiti in this place though, and some pretty rad photo ops. Also again, security is pretty much nil
---------------------------------------------------------
The Art Mill
Same as the last two. This place has some of the most amazing graffiti I've ever seen. Check it out if you recognize it.
-------------------------------------------------------
Seekonk River Bascule Bridge
Zero security. This bridge has been stuck in the 'up' position for decades. Awesome place to bring people new to the hobby
-----------------------------------------------------
The Old Power Plant
This place does have security, but entrance is possible. Just be careful. The building is just a shell of what it once was, completely gutted. Only the view from the roof makes this one worth it
That's all for now.