A list of all of the locations where you can find a Piece of Heart in The Legend of Zelda: Oracle of Seasons.

Piece of Heart 1: Horon Village

Required Items: Seed Satchel and Ember Seeds

Go north from Vasu's Jewelers and use an Ember Seed on the small tree to reach the Heart Container.

Piece of Heart 2: Maple

Maple has a chance of dropping a Piece of Heart when you bump into her. After you get a Piece of Heart from her, she won't drop Pieces of Heart anymore.

Piece of Heart 3: Gasha Tree

There is a chance of getting a Piece of Heart from a Gasha Tree at a rank 4 location. See the list of soft soil locations to check where to find these rank 4 locations. After you get a Piece of Heart from a Gasha Tree, you won't get Pieces of Heart from Gasha Trees anymore.

Piece of Heart 4: Eastern Suburbs

Required Items: Power of Winter, Seed Satchel, Ember Seeds

Go east from Horon Village until you reach a tree stump. Turn it to winter, then go north and up the stairs, and walk across the snow. Go south and enter the cave to find a Piece of Heart.

Piece of Heart 5: Subrosian Market

You can get a Piece of Heart from the Subrosian Market for 20 Ore Chunks and 10 Ember Seeds. You can reach the Subrosian Market after you complete the Snake's Remains dungeon. You can get Ore Chunks by digging in the ground in Subrosia.

Piece of Heart 6: Woods of Winter

Required Items: Power Bracelet

In the southeast part of the Woods of Winter (northeast of Horon Village), use the Power Bracelet to lift the stone, then take the Piece of Heart.

Piece of Heart 7: Moblin's Keep

Required Items: Animal companion flute

After you get a flute of an animal companion, go to the Scent Seed tree northwest of Blaino's Gym (it's north from the guy whose cat is stuck in the tree, which is east of Impa's House). Go east from the Scent Seed tree, then summon your animal companion and go north. With your animal companion, go to the southeast part of the area, where there is a sign and a cannon. Go up the stairs east of the cannon, then go north, then northwest and enter the keep. Pick up the bombs thrown by the Moblin and throw them back at him. You will have to do this very quickly at the end to make a bomb explode on the Moblin while he is still holding a bomb. Afterward, open the chest to get a Piece of Heart.

Piece of Heart 8: Mt. Cucco

Required Items: Zora's Flippers, Power of Spring

Go to the Sunken City and dive underwater to reach Mt. Cucco. Climb up the vines and go north to see a Piece of Heart. Go east and use the tree stump to turn it to spring, then go west until you find a flower that you can stand on to make it launch you up to the ledge. From there, go east until you find another tree stump. Go south from the tree stump to fall down a ledge. You will land next to a Piece of Heart.

Piece of Heart 9: Spool Swamp

Required Items: Zora's Flippers, Power of Spring

In Spool Swamp, go to where you can see the entrance of the Poison Moth's Lair (west of the house in the northern part of the swamp), and use the tree stump to turn it to spring. Make your way southward until you find the Piece of Heart in the middle of the swamp. You can reach it in spring, when the vines have disappeared.

Piece of Heart 10: Eyeglass Lake

Talon and Malon's house is northeast of Gnarled Root Dungeon (the first dungeon). Go south from Talon and Malon's house and jump over the holes in the ground. Go east, then north, and use the tree stump to turn it to summer. Go east, then south until you can go down the stairs into the drained pond east of Eyeglass Lake. Go down the stairs and make your way through the cave, being careful to dodge the spears in the final room, and open the chest to get a Piece of Heart.

Piece of Heart 11: Graveyard

After you complete the Explorer's Crypt dungeon, go through the house north of the pirate ship to reach the tree stump. Stand on it and turn it to autumn. Go back through the house, then go west from the pirate ship and enter the cave. Use the Roc's Cape to jump across. Push the rightmost block up, and the block to your left left. Go up the stairs and you'll be in the graveyard again. Go to the northwest corner and lift the mushrooms, then go northeast. Get the Piece of Heart.

Piece of Heart 12: Temple Remains

After you drop a bomb into the hole in the Subrosian Cave and fill the Temple Remains with lava, go back to the Temple Remains, and go north. Use the Roc's Cape to jump over the lava and reach the cracked wall. Bomb it and go in. Use the Roc's Cape to jump to the Piece of Heart in the top middle of the room.