There's just one catch. Each Great Fairy you find wants a larger amount of rupees: the first will cost you 100 rupees, the second will cost you 500 rupees, the third will cost you 1,000 rupees, and the fourth will cost an eye-watering 10,000 rupees – so you might want to check out our guide on how to farm rupees quickly.
Great Fairy Cotera
Start at Kakariko Village or the Ta'loh Naeg Shrine, and head up the hill into the forest.
This fountain is surrounded by Blue Nightshade.
Great Fairy Miya
Glide east from Dah Hesho Shrine in the Akkala region.
This fountain is surrounded by Armoranth.
Great Fairy Kaysa
You can spot this one pretty easily while standing on Tabantha Tower.
This fountain is surrounded by Mighty Thistle, and there's also some ore deposits to the left.
Great Fairy Tera
This is the trickiest one to get to.
Take some cooling items (drop some meat in the snow if you're stuck) and head south west from Gerudo Town. You'll also find Hawa Koth Shrine, and one of the leviathan skeletons you'll need to photograph for a side quest here.
This fountain is surrounded by Warm Safflina, Electric Safflina, and Cool Safflina.
Don't miss our other guides to The Legend of Zelda: Breath of the Wild.