The treasure chest in the Bear Cave can provide green cards. When entering in a group and planning to clear the card room first, the Bear Cave is also a good choice in addition to the highly competitive key facilities.
Bear caves with treasure chests inside and cabins where green cards can be obtained may be scattered around the map, such as Traveler Hills or Frozen Plains.
As for whether the Bear Cave, etc., exist at a fixed location in each game like key landmarks, or whether they will be randomly generated at the start, this has not yet been verified.
Although bears are dangerous, players will not be actively attacked if they keep a certain distance from the bear cave.
If the player brings equipment, especially a gun, it will be very simple to kill a bear and open the box to get a green card, and he can also harvest the hide and so on.