[Holowtinns Bank]

The goblin proceeds to explain things! Not any more than your average customer would get, both from being told by the goblins and what they'd see going down into the tunnels.

This includes that there are staff on site all hours of the day (but not any specific numbers), a general idea of the extent of the tunnels (which are very large and extensive), the fact that the tunnels are most often pitch black save for guiding lanterns, the rail is suspended above the cavern floor, that the vaults can only be opened under specific circumstances that vary by vault depth, and that the security gets better the deeper you go.

Other details can be worked out and filled in OoC, but that's a good chunk of it.