"Mount Nighon" is actually Mount Thunderfist. Both sets of tunnels terminate there, the one from beneath Stone City, and the one leading to Eeofol. Steelehand's directions are good, but if you want to start from the entrance where you most likely exited after your journey from Stone City, you want to head roughly south and then follow the tunnels that lead eastwards and down. Eventually, you should find some huge open caves. You come into these at the south, and the tunnels to Eeofol lead away from the north of that section.I would advise you to be careful. If you think the tunnels under Mount Thunderfist are bad, then the ones to Eeofol are dire. If you're having trouble with the former, then your party won't be tough enough to survive the latter. There are tricks you can use to make it easier, but you're unlikely to use then successfully at the first time of asking. You need to have some knowledge of the layout. One advantage I did find was that the tunnels themselves are less confusing that the ones from Stone City. But that's just about the only advantage there is.
