|This article is about a/an lair in Power Rangers Megaforce.|
The Underground Cavern is a vast subterranean set of caves and tunnels, which serves as the main base of operations for the Toxic Mutants. It is located in the long chain of forested mountains that surround Harwood County and is also situated near a large freshwater lake, in which some of their kind also reside.
It is also a very advantageous vantage point and allows the Toxic Mutants to monitor the war against the Mega Rangers through the openings of the aggregate, similarly to the viewing screens of the Warstar Spaceship and the Underwater Laboratory.
Although a somewhat commonplace location, only Bluefur, Bigs and Vrak are shown to be constantly within the system, with the lesser Toxic Mutants usually living in the immediate vicinity, concealing themselves underground, underwater and amid the trees of the cincturing grove.
After they are defeated by the Mega Rangers, the place is seemingly deserted permanently and not accessed again after Vrak briefly revisits the area to test the usage of his enhanced Zombolts to enlarge Rotox DX before his final confrontation against the Gosei Ultimate and Gosei Grand Megazords.