Go up the stairs and go left. Talk to the Nabooru (the Gerudo). When questioned, say Nothing, Really, and no, and then you'll be asked to get a treasure. Crawl through the crawlspace, kill the keese and armos, and then light a Deku stick with one of the torches. Go through the right hand door and light the torches in there. Then go back and go through the other door. You'll have to fight a Stalfos here and also a green skull, just stun it with your boomerang and then hit it with your slingshot. 

Now throw your boomerang to the left of the switch across the pit from you. If you aim right it will swing around behind the fence and hit it. Then the fence will fall down forming a bridge. Cross the bridge while watching out for flying pots, and go through the next door. In this room walk along the bridge until before the spike thing and then hit a switch and lure the guy into the flame. There's nothing on the other side of the bridge, just go through the next door. 

Open the treasure chest here for a small key and collect all the silver rupees to make the bridge. Now go back into the first room again and this time climb through the small hole (not the one you came in through, the one between torches). Go through the locked door. Kill the skulltulas and climb up the wall. Go in the room a ways and you'll have to fight two lizardons. Use your boomerang to hit the switch above you and open the chests that appear. One has Bombchus in it, the other a Deku Shield or 5 rupees. Aim a Bombchu so it climbs up the wall and hits the boulder up there. This will open the doorway. Go in and look to your left. Push the stone statue you see off the ledge onto the switch. Climb the steps in front of you to get to a torch and a door. 

Light a Deku stick with the torch, drop down, and light the two torches in front of the big statue to get the Map. Go back to the small statue, climb the wall, and go up the steps again, this time going through the door. Go around to the next door, and now you have to collect more silver rupees. You'll have to kill the Beamos with bombs or bombchus to get up to most of them. After getting them all a torch will light. Use it to light the other torches to get a key.