The EX Ancient Horse Rumors quest is one of many new missions added as part of Zelda: Breath of the Wild's second DLC pack.
Playing it through will take you to the Ancient Saddle and Ancient Bridle, two upgrades to your horse.
As well as the below we have pages on Dark Armor, Usuper King, Garb of Winds, Merchant Hood, Royal Guard Rumors as well as a Zelda: Breath of the Wild DLC 2: Champions' Ballad guide.
Or, if you're after help for the main game itself, consult our Zelda: Breath of the Wild walkthrough and guide.
Ancient Saddle quest
This part of EX Ancient Horse Rumors quest isn't located too far from where you found the journal at the start of this quest. You should have unlocked the Ka'o Makagh Shrine while visiting the Highland Stable, if not, you'll find it on a ridge overlooking the stables. If you've already unlocked it, fast travel over, and head south east.
Use the mountain behind the shrine to cross over to Lake of the Horse God and land on the bridge that crosses it. Follow the trail that leads into the mountains and you'll find a giant plant pod. Behind it, you'll see a chest half buried in the mud. If you can't make it, turn on Magnesis and it should glow pink. Pull the chest free and open it to add the Ancient Saddle to your inventory.
To use both items, you'll need to have reached a maximum bond with any regular horse in Hyrule. Then approach a stable hand at one of the stables and you'll be able to swap the bridle and saddle out for these special new ones. They're particularly useful as they add two new spurs and enable you to teleport your horse to you, regardless of how far apart you are.
Want more help? Our Zelda: Breath of the Wild walkthrough and guide steps to completing the game's main quests - including Divine Beasts Vah Ruta, Vah Rudiana, Vah Medoh and Vah Naboris - as well as how to find the Master Sword, Hylian Shield and all Captured Memories locations and Great Fairy Fountain locations, while our Shrines locations and Shrine maps hub explains where to find and solve every puzzle room, including dragon locations and Labyrinth solutions. We also have advice on how to beat Guardians, where to get easy Rupees, tame horses, find how to get cold resistance, fire resistance and heat resistance, and learn the most effective means of cooking with ingredients for bonus effects. We also have a DLC 1 guide and DLC 2 guide, including all Tingle, Majora's Mask, Phantom, Midna outfit locations.
Ancient Bridle quest
Unlike the Ancient Saddle, the Ancient Bridle requires a little more travel. The item is located high up in the Satori Mountains, which you can find just south of Hyrule Bridge (located in the Ridgeland Region of Hyrule).
If you're still struggling to find it, don't worry - there's actually a shrine located at the bottom of the Satori Mountains known as the Mogg Latan Shrine.
All you need to do is warp here, climb to the very top and look for a small lake with a large tree overlooking it (you should encounter a unicorn while you're here). The chest is buried in the ground at the foot of this tree. Use Magnesis to pull it out and the Ancient Bridle is yours.