Preparing The Passageway
John had no earthly idea what condition the structure might be in, after sitting unused for decades. So he knew that he and his friends needed to reinforce the entire concrete entrance and repair it where necessary.

The spiral staircase leading down into the underground space also needed some serious attention. The metal steps were almost completely rusted through and not safe to stand on yet. They could even collapse if someone tried to use them in their current condition.
Regardless of these necessary delays, John was getting closer to solving the mystery!