The Cistern Chapel (formerly Cave of the Silver Statuette) is a dungeon in Dragon Quest IV. It is not necessary to enter this dungeon, but it holds a Silver Goddess statue that can be sold to a villager in Endor for a significant sum of money.
The "chapel" is a cave filled with channels of flowing water, which must be raised and lowered to properly spelunk its depths. If Hardie is present, he will mention that he has been hired as protection by many would-be treasure hunters in the past and that none of them have so much as caught a glimpse of the statue before being forced to retreat.
Usage of the dungeon in another area