Acquisition of an item Inside One's Property - Kinyan Chatzeir
In General
This method Requires that the Owner be there to guard his Property: Bava Metzia 11a-b
If the area is guarded, acquisition doesn't require the owner's knowledge: Bava Metzia 11a
Who owns produce growing on an incline between two fields: Gittin 22a
If the item is being Given [and not merely Claimed] then the field does not need to be guarded: Bava Metzia 11b
If the item is being Given [and not merely Claimed], the Owner does not have to be able to reach the entity before any pursuers would: Bava Metzia 11b, 12a