Here is a Map of a Pumped System in South Germany / Black...

Here is a Map of a Pumped System in South Germany / Black Forest.

Names with the word 'Becken' " Pool " are part of the system.



In winter of 1977/78 I went to see a friend that worked on the underground system of the Eggberg-becken...

He took me for a guided below ground view ...was nice and warm below ground...freezing cold above ground.

https://www.google.com.au/search?q=...AhUNY1AKHeSNCacQ9QEIUDAC#imgrc=-Ils1cTD9D6loM: