There are two mines in this game. One is the lake mine and the other is the winter mine.
The winter mine is only allowed into in the winter when the lake my mother;s hill is frozen over. Here is more valuable gems and some cursed tools.
The lake mine is by the hot springs. Here is less valuable items.
In the winter mine, sometimes there is no floors. It may stop.
To go through the mines, hammer rocks to find gems and hoe the ground to find the staircase leading lower in the mines.
Both mines are 255 levels deep.