Link's Awakening Heart Pieces (Game Boy)
Link's Awakening and Link's Awakening DX feature 12 Piece of Heart hidden across Koholint Island. These, combined with the 3 hearts Link starts the game with, and the 8 Heart Containers obtained from the various Temples, allow Link to achieve a maximum of 14 hearts.
For the 2019 remake for Nintendo Switch where there are 32 Pieces of Heart, view that particular Heart Piece Guide.
Location: Mabe Village
Conditions: Acquire the SwordHeart Piece #1: Two screens west from Marin and Tarin's House, there are three bushes above a cliff leading to a well. Cut down the middle bush and jump into the well, which will take you to a small cave containing a Piece of Heart.
Location: Mabe Village
Conditions: Enough Rupees to fish (10)Heart Piece #2: Located two screens north from Madam MeowMeow's house is a fishing pond. The fisherman will charge you 10 Rupees to fish there. In the pond there are three small fish, and two larger ones. The big one that floats directly beneath where Link stands is the heaviest in the pond, and carries a Piece of Heart with it. Catching it almost always requires you to first catch the smaller fish swimming above the rest, rewarding you with 5 Rupees. After that, cast your line and reel it in atop the water so that it doesn't sink and get taken by another fish, then let it sink down to the fish under the cliff.
Location: Koholint Prairie
Conditions: Acquire Roc's FeatherHeart Piece #3: Exiting the Mysterious Woods to the east brings Link to a Piece of Heart surrounded by a ring of bottomless pits. Simply jump over one of the pits to grab it.
Location: Mysterious Woods
Conditions: Acquire the Power BraceletHeart Piece #4: In the tunnel that leads to the area where you got the Toadstool, there are two skulls blocking the way to a Heart Piece. Pick them up using the Power Bracelet, and cast them aside to get to it.
Location: Ukuku Prairie
Conditions: Acquire Pegasus Boots, BombsHeart Piece #5: In an area near some pits with a few Pincers hiding in them, you will notice a weak wall on the upper-left side of the screen. Bombing it reveals a cave with some green crystals which you must dash through using the Pegasus Boots and having your Sword equipped on the other button. There is a hidden weak spot in the wall on the eastern portion of the cave. Bombing it reveals a smaller section with a Piece of Heart in it.
Location: Yarna Desert
Conditions: Acquire BombsHeart Piece #6: This area is found by either sinking into the quicksand where you fight the Desert Lanmola, or by going one screen east of this area and bombing a wall in the north section. If you sink in the quicksand to get to the cave, use a bomb on the northern wall in that room, which will reveal the section with the Heart Piece. If you go through the bombable wall, just go left one screen to reach this same room.
Conditions: Acquire Roc's FeatherHeart Piece #7: There is an area which has four graves here. The bottom-right grave can be pushed upward to reveal a cave. Normally, you would have to use other items, such as the Hookshot and Bombs to get to this Piece of Heart (at least that's apparently what the creators intended). However, really all you need to do is a diagonal jump from the area where you walk out of the stairs to the south-east platform, then jump to the area containing the Piece of Heart just above that. You can exit the same way you got there, or just fall down a hole and re-spawn back at the staircase.
Location: Tal Tal Heights
Conditions: Acquire the FlippersHeart Piece #8: Located three screens east of Level 4, Angler's Tunnel, is a cave. You need the Flippers to swim in the deep water to get there. Once you get inside the cave, go up a couple of strokes and dive to discover this Heart Piece.
Location: Kanalet Castle
Conditions: Acquire the FlippersHeart Piece #9: In the north-east section of Kanalet Castle's outer edges you will find a staircase leading into the water, and another staircase just ahead of it. Enter the water by way of this staircase, and go 3 screens left and 4 screens down. You will now be in the moat in front of some pits and a stairwell. Swim along the edge next to the hill where the pits are and dive down in front of the second pit. There, you will find another Piece of Heart.
Location: Animal Village
Conditions: Acquire the Hookshot, Bow, Roc's Feather, Bombs
Heart Piece #10: When entering Animal Village, go directly south to a blockade of bushes. Cut them down to clear the path which leads to Yarna Desert. When you reach the screen where the Walrus is lying early in the game, take the path north, which leads to a weak spot in a wall. Use a bomb on this spot to enter the cave.Once inside, go one room left by jumping over the pit, then one room up. You will see a pit and a cracked rock on the other side. Go back to the first room, and bomb the north wall. Walk in, and you'll be on the other side of the fence that's in the room with the Piece of Heart. Throw a Bomb over the fence to blow up the rock. Alternatively, a Bomb Arrow may be used to destroy the rock from the other side. Go back to the other side. Then, use the Hookshot to grab onto the solid rock behind it, pulling yourself across the pit. Walk up the steps to retrieve the Heart Piece.
Location: Tal Tal Heights
Location: Turtle Rock
Conditions: NoneHeart Piece #12: The final Piece of Heart is in the last dungeon of the game: Turtle Rock. It is located in the upper-left section of the map, in an area that would seemingly be the left arm of the turtle (as the map does resemble a turtle's body). Simply climb the staircase in this room to go outside of the dungeon to reach a section of Tal Tal Mountain Range where the Heart Piece will be found.