Monster's Den is one of the game's buildings. It is unlocked at Kingdom Level 12.
It features two modes, both part of the Daily Tasks:
- Boss Clash: Visually similar to the Fighting Pits and using your Battle Power to decide victory, but your soldiers are effectively lost when killed. Remember to recruit plenty at the barracks before starting.
- Blitz Acres: A special, almost endless battle. It includes all enemies and bosses from the World Map (also has some exclusive enemies).