Romancing SaGa 2 (HP)

When entering Salamat (dense jungle) if you take the upper right exit, you will wind up in a village with some docks in the northern part. The boatman will offer to take you to Tsukjima if you talk with him. While in the new town, speak with all the villagers and one of them will mention a city of salamanders on the other side of the volcano. You can visit this city and look around. Don't forget to get the stone boat in salamat to be able to traverse the lava. Stopping the eruption will end your business here for now but you will need to return later for the achievement. Eventually when you start a new generation your minister will mention that the volcano is ready to erupt again. Go back to Tsukjima and talk to the towns people. Visit the Salamander chief and he will tell you to evacuate the human town. Speak with the mayor in the human town and they will evacuate. Go back to the lizard chief and he will tell you to remove the plug in the volcano and give you a hammer. Head back to the top of the volcano and beat the weird boss. The lava will be flowing in the salamander town again. Speak with the chief and the achievement should pop.