Basically just a small area that if you kill enough monsters inside it could spawn in a special enemy.
Probably would also be able to be placed by players, HOWEVER THEY CAN ONLY SPAWN ONE
Kill at least 50-100 enemies inside of this to summon:
Demon Spider Boss (rare)
Spider Boss (common)
This could also be like a portal area where a rune symbol is inside and you have to kill a lot of enemies to unlock it
Sacrifice Requiring Portal (ᛃ)
Kill 50 of each enemy in the area to open.
(if in Enchanted Forest)
Can lead to any area before
Can lead to some areas after
My ideas are probably stupid especially with the renting one but I hope it’s at least interesting