In The Legend of Zelda: Tears of the Kingdom, stables will play an important role in Link’s quest to take down the demon king. They offer a bed to rest his weary head along with the ability to board horses which can make traversing Hyrule a breeze. There is even a reward system dubbed Pony Points that you can earn by using the services available at stables. Unfortunately, the stable in Lookout Landing will be unavailable right away.
Before you can unlock the mini-stable, you’ll first need to complete one of the four major dungeons during the Regional Phenomena main quest. After this has been done, return to Lookout Landing and head for the in-progress table near the southern exit. Speak with Karson and you should get the Incomplete Stable side quest. Complete it by climbing on the stack of hay bales behind the stable then use Ultrahand to fit the final piece of roof into the slot. Speak with him afterward and the quest will complete with the stable being open for business.