This page explains how to find the Katah Chuki shrine.
How to Find the Shrine
This shrine can be seen from the top of Central Tower if you look north. The shrine is southwest of Hyrule Castle.
Treasure Chest in the Shrine
This is a Minor Test of Strength shrine. The Guardian Scout wields a Guardian Spear. After you kill the Guardian Scout, open the treasure chest to get a Royal Halberd.