How many feet is that from where they are building the raise?
It is not directly above the "tunnel"
Which "tunnel" in the 7 miles of tunnel are you talking about?
So lets see more than assumptions and speculation. Use the information given and give us the exact location to the terrace. You can use a 3 figure location. Longitude latitude and depth.
Show me where the gold is. Show me a link saying "gold is 60 feet away"