The Serene Caverns
The Serene Carverns the only cave system that traverses the majority of the Dragonfire Lands. The easiest entrance is along the shore of the King Depths south of Deepholc. According to the records we could find the system has only been traversed from the entrance south of Deepholc to the enterance near the Giant steps and Rockham one time in the year 325.
Legends say that the caverns were first discovered in -5,951 by Smeak Ticel. It wasn't until 291 that the caverns began seeing regular use.
Entrances
Mines
The easiest entrance for most to use is off the coast of the King's Depths. As of the writing of this report, the eastern entrance serves as the base of operations for Y'on Mining Group. The current forman claims that whenever they remove a vein of gems from the mines, another vein seems to take it's place.
This of course has led to many miners getting lost in the caverns, some never coming back at all. In order to help mitigate this risk, the miners have taken to remaining on a harnass of sorts, allowing them to follow a lead back to the entrance of the mine.
Oooh this place sounds awesome to explore, but best only done if you have a way to teleport out if you get lost... So, who wants to go visit a Minotaur?
Too low they build who build beneath the stars - Edward Young
Funnily enough the party is actually on their way to visit a Minotaur as we speak. Something about saving a fish?