Something remarkable will be lost to time
A tunnel leading under the strip will be buried when they level the New Frontier.
It is probably one of the last accessible tunnels under the Strip.
The tunnels are a time capsule of sorts, where Siegfried and Roy used to traverse to the other side of Las Vegas Blvd to the other side, to avoid the crowds.  I know Bugsy Segal had tunnels built under the Flamingo (for escaping the IRS).
I haven't found much literature on these tunnels.
In the 70's Howard Hughs owned Summa (summa is latin for highest).
Summa owned the Desert Inn, Sands, Landmark, Castaways, Silver Slipper, and the Frontier. It also owned KLAS TV. I still remember the late night movies with breast showing all ablaze. Hughes would call the station and have them play movies for him. I believe Summerlin was named after Summa.
The Frontier is the last hotel remaining from the old Summa empire.
Summa, whose headquarters is on Industrial road, at one time, had contracts with the CIA. Back in the 80's, I had heard the stories when I consulted with Summa for NABS. I saw evidence of it, both at the Industrial complex, and the complex at Spencer an Flamingo.
I have heard one of the access ways to the network of tunnels is in Frontier's basement.
See. So. I almost have to go explore.