Mabe Village Well
Once you have your sword, you can cut the bushes above the well in northwest Mabe Village. If you cut the bushes, you can jump down into the well. It is a rough landing, but jumping into the well will reward you with a Piece of Heart.
Mabe Village Fishing Pond
North of BowWow’s house in Mabe Village there is a fisherman who will offer to let you play a fishing mini-game for 10 rupees.
The pond always has three small fish and two large fish. Catching the large fish on the right side of the screen will reward you with a Piece of Heart.
There’s a very good chance you’ll catch at least one (and possibly all three) of the small fish before you can catch the larger fish. You will be rewarded five rupees each time you catch a small fish and 20 rupees each time you catch a large fish.
You will pass this Piece of Heart on your first visit to the Mysterious Woods, but you cannot retrieve it until you have Roc’s Feather from Tail Cave. It is almost impossible to miss this Piece of Heart because you will have to walk over it to save BowWow prior to entering Bottle Grotto, the second dungeon.
Use Roc’s Feather to jump over the holes blocking your way to the Piece of Heart.
This is another Piece of Heart that you will pass on your first visit to the Mysterious Woods. There is a cave that leads to the Sleepy Toadstool with a Piece of Heart inside. Once you have the Power Bracelet from Bottle Grotto you can lift the two skulls that block the way.
Once you have the Pegasus Boots, look for a cave east of Mabe Village, in Ukukku Prairie, that you must use a Bomb to open. The exact location is one area west of the tree with the Honeycomb in it.
Inside the cave, you will find a treasure chest, two Sparks, and several of the crystal blocks that can only by destroyed by running through them with the Pegasus Boots.
On the eastern wall of the cave, there is a secret area that you can open with a Bomb. Inside, you will find a Piece of Heart.
After you defeat the Lanmola in the Yarna Desert, there is a good chance that the Angler’s Key will fall down the hole in the center of the room. If it does, you’ll have to fall down the hole to retrieve it, but even if the key does not fall you should.
You will fall into a cave with various holes in the ground. Place a Bomb on the northern wall to reveal a hidden room with a Piece of Heart inside.
Angler’s Tunnel Cave
After completing Angler’s Tunnel, use your new flippers to swim directly east until you find a cave. The cave is empty, but if you dive near the center you will find a Piece of Heart.
You can reach the same cave by jumping off the cliff directly south of the entrance to Eagle Tower. Jumping will cause you to fall down a hole that leads into the cave that contains the Piece of Heart. It is also possible to fall into the hole while exploring Tal Tal Heights without jumping off the cliff.
Kanalet Castle Moat
Once you have the flippers, you can swim around the Kanalet Castle moat. If you enter from the north you can reach the southwest corner of the moat. Once you arrive in the southwest corner, begin diving around the area and you will find a Piece of Heart.
South of witch’s hut there is a staircase leading underground that is surrounded by a circle of stones. Use the Power Bracelet to lift the stones and enter the underground passage. On the eastern end of the passage there is a Piece of Heart in plain sight but out of reach. To reach it, use a bomb to destroy the cracked block that is blocking your path and then use the Hookshot and Roc’s Feather to reach the Piece of Heart across the large pit.
There is a cave in the northeast corner of Animal Village that contains a Piece of Heart. The entrance is closed, so you must use a bomb to open the cave. Inside, you will find a long pit that cannot be crossed because there is a cracked block on the western end.
You can destroy the cracked block with a bomb-tipped arrow. Equip the bombs and bow and then press both buttons at once to fire an explosive arrow that will destroyed the cracked block. You can then use the Hookshot to cross the large pit and retrieve the Piece of Heart.
Tal Tal Heights
There’s a good chance you will notice this Piece of Heart on trips up the mountain, but it can be tricky to figure out how to obtain it.
On your way to Turtle Rock you will cross a bridge with the Hookshot and end up at a dead end with a single bush. When you cut down the bush, you’ll find a passage in the mountain.
Bomb the southern wall of the passage to open a new route that leads to a Piece of Heart.
While exploring the eighth dungeon, Turtle Rock, you will find a staircase that leads outside the dungeon (a back door). Outside, you will find the fourth teleporter, a new entrance to the dungeon, and the final Piece of Heart.