adit

"As soon as you go in through that adit, you could literally be back in the 1800s," he said.

The kiosk nearby describes this as an “adit,” a short tunnel that was used to gain access to the center of one of the twin tunnels during construction.

Fluke said he noticed two collapsed mine adits, or what appear to be, while hiking in Cardiff that he brought to the attention of other state agencies and the EPA.

Garrett Wake, Division of Minerals southern Nevada chief, classified Roman’s home as an adit - a horizontal opening in a hillside that he said didn’t present much of a danger.

Lina points to a low tunnel leading off the main passage, an access adit perhaps two feet high.