City of Miami, FL City Monument lines....

Looks like i'm driving for 3 hours south to downtown Miami tomorrow. We're platting a piece of OLD property and the City want's us to show the "City Monument Line". It's basically a reference line to the intersection centerlines and section lines. So i have to go to City Hall and try to figure out how to get the plats that show this, as well as the city limits line. Anyone been down there to do this and what exactly are these "plats" or plans called. I don't speak spanish, so i figure it's an all day thing.....