Ganon exercised his chilling powers by causing the lake in the southwast to freeze and by creating a storm cloud to cover the area with snow. It serves adventurers of this region well to wear geat that will protect them from the elements.
Points of interest
The creatures who survived the sudden change of weather are said to be very tough. Zirros and Pikits rule on the land, and a band of Zora's Spawn took over the cold waters of the lake. The subjects of the Golden Land who survived stay in caves and buildings.
Item Shop
The Item Shop in this region is stocked with the standard goods. Adventurers in need of Potions, Bombs, or a Shield can stock up here. The Potion is especially useful as enemies in this area are dangerous.
Storyteller
The odd creature in the cave on the northeast shore of the lake will confess to having been a former thief. For a price of 20 Rupees, he will tell visitors the story of another former thief who was an old friend of his that could open locked Treasure Chests with ease.
Odds and ends
The next crystal that you wish to obtain can be found in the Ice Palace. But before we dive right in, there are a few errands that you can take care of, especially now that you have the Titan's Mitt.
Reunion of the Blacksmiths
From the earliest moments of your quest, you heard about a sad blacksmith near Kakariko Village. The poor fellow has lost his partner and could no longer excel at his craft. Not until you reach that Dark World, however, can you help the blacksmith. During one of your explorations south of the village, you may find a frog trapped by skulls. If you free the frog, you can take it back to the blacksmith. Upon his return to the Light World, the frog will be restored to his former blacksmith self. The two partners will be overjoyed to be reunited after so many years apart. In a display of gratitude, they will take your Master Sword and strengthen it. It will take some time, but you will receive the 
Tempered Sword in return.
The well by the Smithy
Outside the Smith's house near the village is a stake blocking a place where you can jump into a well. Using the Magic Hammer, pound the stake and jump into the well. In the well, sprinkle magic powder on the statue. You will find a strange creature who claims to take away half of your magic power when, in fact, he actually doubles it.
Unlocking a secret
The blacksmith's house in the Dark World is a shattered shell in which a locked trunk sits. When you discover the trunk, you won't find a key to open it with, and whacking the trunk with your sword does nothing. If you spoke to the storyteller near the Ice Palace, you might recall heaving about the thief who is said to be near the desert. Drag the trunk to the sleeping man in the canyon. The man will wake up and open the trunk. Inside, you will find the fourth 
Bottle.
Disappearing Link
The Graveyard in Hyrule holds deep and hidden secrets. Most mysterious of all the tombstones is the large tombstone blocked off in its own private plot. One you obtain the Titan's Mitt, you can return to the graveyard and gain access to the large tombstone by lifting the dark rocks. Pushing against the stone won't yield much, but a Dash Bash against it will force the tombstone to slide back, revealing a hidden chamber below. In that chamber, you will find the 
Magic Cape, which will render you invisible when you don the cape.
An impassable situation
Near Death Mountain in the Dark World, you may have come upon a sign promising to reward the person who wears the Cape with a Piece of Heart. In the mountain cave nearby, follow the passage until it is blocked by a bumper. Don the Cape and slip past the bumper to reach the 
Piece of Heart beyond.
The Ice Lake circle
Northwest of the Ice Palace lies a circular arrangement of stone which surround a shallow portion of the lake. Just as you learned near the Swamp Palace, there are strong relationships between the Dark World and the Light World. Swim to the shallow section inside the circle and use your Magic Mirror. If you do, you should end up on top of the island in the middle of Lake Hylia that contains another Piece of Heart.
The Way to Ice Island
No matter how long you battle the dive-bombing Zirros and other creatures of Ice Lake, you will not discover a way to enter the Ice Island dungeon from the outside. Instead, if you visit the central island in Lake Hylia which is in the same location as Ice Island, you may discover the Warp Tile concealed under the dark stone. The Warp Tile will transport you to the inner courtyard of Ice Island.
Ice Palace
Since the Ice Palace is a very cold place and populated by creatures who were created by the magic of ice and snow, it only makes sense that a warm weapon will be quite useful. Those explorers who have command of the Fire Rod qill find this device to be very useful in the chambers of the Ice Palace. A supply of Potions is also good to have as the enemies are very strong and in large abundance. The villian, Kholdstare lurks deep in the palace dungeons.