Loot Chest Underground Near East Side Of Mt. Wynn?

Although this chest might be gone as it was awhile ago, I remember that a loot chest was in some sort of little underground cave area near Mt.Wynn. Another player told me to stand on a block while he/she pressed a button that I couldn't see. A hole opened up where I was standing, fell into a little cave, and I opened a loot chest. Pretty sure their also was an exit button, but this was months ago. Anyone hear of this?

 

um sounds like the relic spot
but nope no idea wut ur talking about