It seems that there are two differents Location objects:

- global class Location extends SObject 
- global class System.Location 

Because System is the default namespace, I can not refer to the SObject *Location* in APEX. 

Example (in Location trigger):

    Map<Id, Location> newLocations = (Map<Id, Location>) Trigger.newMap;

--> *Incompatible types since an instance of Map<Id,SObject> is never an instance of Map<Id,System.Location>*

Is there any way for me to get those SObject ?