Shenzhen border, Visa On Arrival limit

Hello ! I all time stay in Shenzhen with the VOA, bought al Lou Hu Station. Does anybody has a map of Shenzhen with the area limit is shown. I know the airport is included but some company are after the airport. Google maps shows a wide area when entering only 'Shenzhen' as keyword.
I've heard that I can get big trouble when police find me outside Shenzhen without correct entry permit.
Thanks in advance