Regions, regions… “when the player is in SomeRegion” will work.
(There is no single “region” value, because regions can nest, so you can be in several regions at once. This is not true of “location”, because rooms never nest.)
Note that there’s a difference: “the player is in the Kitchen” is true only if the player is directly in the room, and not for example when sitting on a chair that’s in the kitchen. “The location” on the other hand always refers to the room.