Great Fairy Fountains
Great Fairy Fountains are places that allow you to upgrade some items of clothing, allowing greater defense in return for rupees to unlock the location, and items found around Hyrule. There are four Great Fairy Fountains.
The are disguised as giant closed flowers, and the prices for opening them are: 100 rupees, 500 rupees, 1000 rupees, and 10000 rupees.
Cotera's Fountain - North of Kakariko Village, after you teleport to the shrine nearby, it is north-east.
Mija's Fountain - When you warp to the shrine right outside of Tarrey Town, it is in a group of trees, south of the town over the land bridge.
Kaysa's Fountain - Warp to the Tabanth Tower, it is on the ridge to the south of the tower.
Tera's Fountain - This is located next to the shrine on the furthest south-west location in the Gerudo desert, underneath a skeleton.