Otago Mines is located in Cromwell.
Outside of the mine, Nancy must solve a generator puzzle so the sluice machine will work.
There are two entrances tot he mine.
The left entrance splits off into two directions. Going straight leads to a dead end that later opens up to a room with symbols on the wall. Turning off to the right leads to an area where minerals can be excavated and there is a lantern.
The right entrance splits off into two direction as well. Going straight leads to a dead end where a bucket can be found. Turning off to the left leads to a peep hole that shows the room with the symbols on the wall.