Two Korok Seed Puzzles can be found behind bombable walls in the Hyrule Castle Corridors. One is between the Dining Hall and the Square Spiral Staircase. The other is outside of the Guards' Chamber. Link will find a jar hanging from the ceilings in each of these newly revealed rooms. Using Archery, he can shoot the jars, which causes the Koroks to appear and give him Korok Seeds.[3]
In the Movie "An Uneasy Heart", Zelda, Impa, and Terrako can be seen walking through the Hyrule Castle Corridors. After a discussion about King Rhoam with Impa, Zelda sends her to inform Mipha and Daruk of their training the next day.[4] Zelda begins to confide her worries to Terrako, but they are interrupted by Link's arrival.[5]
↑Amongst Hyrule's soldiers, only the best of the best had the honor of guarding the royal family. Apparently, the equipment they wore can still be found somewhere in Hyrule Castle. They say a former maid spoke of treasure near the Dining Hall, in the Guards' Chamber, and on the second floor. — Super Rumor Mill V4 (Breath of the Wild)
↑Father thinks that... He thinks that the reason my ability hasn't awakened is because I haven't worked hard enough. I imagine that when I visit the Divine Beasts, he'll say as much. — Princess Zelda (Hyrule Warriors: Age of Calamity)