I walked by the TV today when some random show was on the travel channel. They were talking about the Rock of Gibraltar and the servers that were 1500 feet below in the cave systems. Right before the show went to commercial they showed a flag with a red castle on it. Forgive me if this has already been cover, just thought it was interesting considering the UK used these servers for their SIGNIT program.

https://www.ft.com/content/979377cc-d7eb-11df-b044-00144feabdc0