You can find the entrances here to the Omicron Turnip Mine and go back to The Crystal Catacombs. In the middle of the room you can find the Corrupt Crystal Core, this houses three crystal critters (Battyfox, Bull Beastie and TwinklePig), you need the fixed Corrupt Crystal Dampener to get them (which disappears after you used it). On the island on the right is a lever (this is needed to get the Flutterbird in this mine).