Ahh, memories.

Wife and I riding "Pike to Bike" an abandoned section of the PA Turnpike that has several tunnels, one of which is several thousand feet long. In June it's not unusual for there to be ice in the middle. It's virtually deserted during the week

We're at one end taking a break and some middle aged guy comes into view coming out of the tunnel where we are, and he didn't have a stitch of clothing on. And he clearly didn't care that we were there. Wife and I to this day remind each other of it....