on call-out, I was woken with the request to go fix an 11/730 with a broken power supply. "Where?" "New-$Placename". Now, $Placename was in my region, so my initial reaction was "OK, but are there any sites there?" "Oh yes, it's the regional ATC for light airplanes." "Hmm, is that really in $Placename?" (I would surely have heard about it). "No, NEW-$Placename. It's near $City".($City was in my region too, so New-$Placename probably was, as well. Never been to that site, though, but that was something that happened occasionally). "Present your passport and your badge at the gate, they know to expect a DEC FS guy"."Oh?" "Yes, it's part of the military base there". "Ah, OK, right. I'll be off now."
So, in my car, past $City, to the site. Gate guards let me in, no problem. "Drive on for some 200 meters, there's a building on the right, the sysadmin will be at the door". "OK, thanks". It's 02:00 or so, pitch dark.
I find the building, park, get shown in, down a lot of stairs, and past several blast doors. Deep in some hardened room there's the 730. The replacement PSU arrives, I extract the broken one, fit the new one, test and that was that. The sysadmin takes me back up all those stairs and out the door, to my car. It's now 05:30, and in the first morning light I see the building has a couple of manned machine gun nests around it. Which was, eh, rather stunning as a couple of hours back I had walked past one quite closely without noticing.
And to top it off that site was actually the responsibility of another region office, but oh well.