Location Tracking in Piwik

Our organizational structure is such that the geographic location is divided into various zones. We have 10 zones defined like middle east asia, south east asia , Pacific and so on.
I want to get the analytic on my website based on the zone. some statics like unique visitors , number of visitors etc from each zone.
We are currently doing that using Cardiolog, How can I achieve that in Piwik ?