How do you get into dragon roost? - Answers

First, go to the Rito Cave and get the Delivery Bag from the Rito there. Then, go upstairs and talk to Medli, who will give you the Father's Letter. Show this letter to Komali (on the bottom floor in the room with green and orange triangles) and then go through the tunnel on the first floor. Throw Medli to the other side of the area you're in when the wind is blowing in that direction, and she'll give you an empty bottle. Fill the bottle with water on the bottom area, and use the water on one of the dry bomb flowers. Use the bomb flower that blooms to blow up the rock, filling up the area with water. Swim to the other side, and throw bomb flowers into the pots there to bring them down. Jump across these platforms to reach Dragon Roost Cavern.