Cache for MKMapView

I am writing an application which overlays results on MKMapView. Thing is the system may not be online all the time, The number of tiles cached be default are limited; i.e. the cache file w开发者_如何学Could have a limited max size. Needed to know:

1. Location of Cache file
2. If i can change the default maximum cache file size
3. If possible, saving different cache files in runtime and loading them as per user requirement(loss of network).

I am not sure how many of these ideas violates license agreement. But since i don't intend to publish it in app store, am not worried about rejection.