The In-isa Shrine is one of the three shrines that you will need to find in order to complete The Closed Door quest objective. A task that is first activated upon The Great Sky Island.
In order to find it we will first need to have completed the Ukouh Shrine first. This will then allow us to make use of the Ultrahand ability.
FINDING THE IN-ISA SHRINE (TEARS OF THE KINGDOM)
After unlocking the Ultrahand ability we can then move on to our second shrine, the In-isa shrine. This particular shrine is situated a little south west of the Ukouh shrine. It is also a little trickier to get to when compared to the previous aforenamed location.
It will require heading towards a small pool of water that features a waterfall gushing from it. It is here where we can find a member of the Kokoro race of species. These are rather small in appearance and often wear leaf themed masks.
RIDING THE ZIPLINE
Though they are also optional we can interact with them in order to begin a small optional objective. This side task will see us having to reunite the two friendly Koroks, who appeared to have been separated from each other.
Regardless of whether you choose to help them or not we need to ride the nearby zipline. In order to be able to do this we will need to make use of the Ultrahand ability. By using this ability we can form and crate a platform that we can ride on. There are many tools and objects at our disposal, including wooden slats and hooks. When you are ready proceed and ride the zipline.
REMEMBER THE WINDSAIL
At this next bit of land we will have yet another zipline to play around with. Except this time one of our tools that we can use seems to form a sailing flag of some kind. Though it does not seem to play much of a role right now, it will do in a short while. So make sure to connect to onto the platform.
Proceed and ride the next zipline. It will lead to a section of water. This is where it will come in handy. Our platform now forms a small boat. A boat that we can use to get across this newly encounter pool of water.
Ride the boat across the water and towards the In-isa shrine.