You’ll need to gain around 5 million gold to stand on in order to reach the key. You’ll see the key in the treasure room in a cubby hold near the ceiling. There is also a special hidden gold key and chest to go with it in the treasure room of the Sanctuary. Once the door opens, you’ll find the gold key inside. Step on the tiles in this order to open the next door: yellow, blue, yellow, red, blue, red, blue, red. You should see some colored floor panels and some flames on the wall that outline the order that you have to step on the tiles. In the next room, use the fireball gauntlet to light the torches. Inside, look for a flit switch above the Enigma door to open it. Near the stairs at the far end of The Veiled Path you’ll find an entrance to The Enigma. Inside you’ll have to fight your way to the gold key. Near the ruins you should find a door that you can unlock using the key you purchased. You’ll come to a cliff side, so follow the cliff left until you find a path near some ruins. Travel to Shifting Sands and cross the sand dunes to the other side. Once you complete the quest, go back to the quest giver and you can buy a key for 4,000 gold. First, complete the A Key to a Greater Key quest in the city, which will be available after the primary story is complete. You’ll need access to the Aurora area to get this gold key. If you went the right way you should find an exit, and find some ruins over a short hill where the key is located. Go through the cave and keep heading on the path going up hill.

To get to this cave, take the path up hill from the lake on the way to Brightwall Village, and take a left on the path before you get there. Two are near the demon door location, and one is off to the side. On the map of Mistpeak Valley, you’ll see three cave entrances for Chillbreath Cavern. Keep following it and it should lead you to a teleporter at the top that will take you to the gold key.

Keep hitting it and it should move around the island. Go accross the bridge and you’ll see a flit switch you can hit. Once these are done, it should open up a bridge to a new island. The quests are called An Island Getaway, Giftwood for Driftwood, and Pest Control.

The first thing you need to do in Driftwood is complete three quests to gain access to the coastal islands. You can access Driftwood after completing the Restoration quest in Millfields.

Fable 3 gold keys and doors