People are commenting core OS libraries and kernels, but the Space Jam movie website from 96 is still up. I bet the guy that wrote that didn't think it'd be around nearly 20 years later, I hope it never goes down.
It's comforting to think that 2000 years from now, all that may remain of the early web and modern culture is the Space Jam website. Maybe Space Jam the movie will be looked at as our Gilgamesh or Iliad.
From the outset, the framing of a Web site as staying "up" (or going "down") is definitely an accessory to the mindset that leads to the effect observed. Rather than regarding Web sites as collections of hypertext-enabled publications like TBL spelled out in "Information Management: A Proposal", we have this conception of a Web page being something like one part software, two parts traditional ephemera. But they're documents. Merely observing this difference in framing and being conscious of the contrast between intent/design and practice can go a long way to addressing the underlying problems that arise from the practice.
https://www.spacejam.com/1996/jam.html