Nest

Nests are the base of various monsters in Strategic Mode. At the nests, monsters will stay here when idle and pirates, brigadiers, and mad scientists will build defenses. Similarly to attacking a city in strategic mode, successfully assaulting a nest requires killing all the enemy constructions in the nest. The rewards for assaulting a nest would be a small reward from the locals, stopping the hampering of city income caused by nests connected to cities (pirates and dragons don't have to be connected), stopping the ability of the monsters inhabiting the nest to attack cities, and possibly the ability to create special units derived from the previous inhabitants of the nest.