"Water treatment plant"
Because when you are treating your water you need a huge radio transmitter and bunker complex!
Ok, perhaps I'm getting a little excited by some of this, perhaps my imagination is running away with me BUT I have it on good authority this "Water treatment plant" was in fact a repeater/numbers station. Why else would it have a huge radio mast and a bunker? The mast is back up and running (not being used for original task), the bunker was sealed up tighter than a ducks chuff but the two identical main buildings at the back of the site were both accessible.
If you're interested:
Numbers Station
Repeater Station
Ok, perhaps I'm getting a little excited by some of this, perhaps my imagination is running away with me BUT I have it on good authority this "Water treatment plant" was in fact a repeater/numbers station. Why else would it have a huge radio mast and a bunker? The mast is back up and running (not being used for original task), the bunker was sealed up tighter than a ducks chuff but the two identical main buildings at the back of the site were both accessible.
If you're interested:
Numbers Station
Repeater Station