The university of Toronto (I was at Ryerson but I had friends going there around 2000) had an active BSD server running for 10 years. Yet nobody knew where the hell it was. Like, physically. They just didn’t know. But it was still responding to their remote requests, running its services and nobody questioned it, because it just kept on working. Flash forward a few years later they were doing some renovations in the engineering building. They tear down one of the walls, and low and behold - a pc with an active network connection. They found the BSD machine.