Secret Glowing Chest in hylotl mission???

i haven't seen anything about this secret chest in the hylotl mission...


This chest is just after the boss fight and have no idea how to get it other than there is a tunnel to get there to the right...

only problem is... I have no idea where the start of the tunnel is...

if you have the upgrades on your M.M. you can see that there is a tunnel and an area to go in there

if you have any idea what it is in the chest or/and how to get in there Please tell me.

 

Time to do some deep diving and edit with a screenie

ED = I don't really remember seeing an ancient chest aside from Erchius and Miniknog so maybe that's from a vanilla dungeon improvement mod or something?

Don't wanna be that person but some can be mischievous and do some admin stuff to remove -> replace something and poof, wild goose chase like that Shadow of the Colossus great search or something = w=

This should be the location you're at as I try to mimic it by removing the glow