Monokoa Island Tropical island (likely in the South Pacific) that was once the site of the mightiest volcanic eruption in the world, courtesy of its central volcano Mt. Monokoa. The volcano laid dormant for 300 years, allowing Monokoa Island to be colonized. Then one day it began to become active once again, threatening to erupt and destroy the island's capitol.
Scientists planned to divert the flow of the lava by lining the high rim of the crater opposite the city with explosive charges, so that when detonated, the molten rock would instead flow down the uninhabited side of Monokoa Island.
When the eruption occured as predicted, debris severed the connection wires of the detonator and the scientists were forced to flee without setting the charges off. Luckily, Superman was on hand to save the day, braving the lava and connecting the wires, setting off the explosives and successfully diverting the lava flow, saving the city.