Other comments have given ways to physically archive the webpage. Continually hosting it is a much trickier endeavor. Beyond just keeping the servers up, technologies will shift such that eventually html webpages, servers that talk using tcp/ip, datacenters that connect via fiber cables, etc will all be deprecated. That said, if we have a very liberal definition of the word "website" to include any successor technolo…
The guts of the box carry a multi array of small, cheap computes's and a very large array of SSDs. Encased in material to protect from damaging scenarios.
The instructions on the outside of the box are diagrams, and text written in all current languages on earth.
A copy of Wikipedia/whatever archive is included. As well as your personal autobiography.
It figures out the healthiest way to stay dormant when not in use. And the healthiest way to use a subset of the hardware in the box to ensure a 500+ lifespan.
Cover plate for interfaces to be removed/opened to use.
If you give a university 1B for a 500 year commitment, that means you're paying the university $5,000 a day to keep that service up.