by littlebro » Mon Nov 30, 2015 12:16 pm
More than one possibility here, as lava pools are all over the place.
Is it about map 3, and you enter down some stairs which brings you into the bottom right corner, with a small rectangular pool just a couple of steps away? If it is, then you need to go up to the steps which go into a lava pool. If you look closely you can just make out that there are "paving stones" through the lava which go left. Follow them to the next set of steps.
Here go down to a patch of solid ground. Continue down for 2-3 steps, go right a few steps and down to a solid island. From the steps at the bottom go left to the steps onto solid ground. Over on the left edge take a step forward which brings you to steps. From there wiggle slightly as you go up, that keeps you on the paving stones. You get to firm ground again and then it's up to the next stairs to the next map.
If this is not where you are, then more details are needed to identify exactly which map you're on.
Effectively it's the same system as got you through the ice cavern in the earlier dungeon on the little island.