The quarry (採石場?) was an area in the southern portion of the village where mineral was being extracted. A mine was also present in this area, being used by the Ganado to imprison a Gigante.
Three huts can be seen around the mining area along with some few equipment for miners to use. A huge door can also be seen, though it was indicate while examine that something quite possibly huge was apparently growling behind it. Upon returning, a group of villagers had awaken the Gigante as they struggle to pull it out, but the Gigante break frees and kill them. Later, Leon fights with the Gigante with a help from a wounded dog who he help from a bear traps
The large door
It looks like the gate's securely shut. Wait. I can hear something growling on the other side.
"Wait. I can here something growling on the other side"