Brings back happy memories. I was there about 20 years ago and went with friends to see the sunset from the rim. Only problem was that we knew they locked the gates to the tunnel at sunset. We got locked in. So we found a payphone and eventually someone who had a key. We had to wait an hour in the tunnel, so we cranked up the radio in the car and played a Brahms Symphony very loud.
I must see if I have any photo's from then.