The first website built was at CERN within the border of France, and was first put online on 6 August 1991:
Info.cern.ch was the address of the world’s first-ever web site and web server, running on a NeXT computer at CERN. The first web page address was http://info.cern.ch/hypertext/WWW/TheProject.html, which centred on information regarding the WWW project. Visitors could learn more about hypertext, technical details for creating their own webpage, and even an explanation on how to search the Web for information. There are no screenshots of this original page and, in any case, changes were made daily to the information available on the page as the WWW project developed. You may find a later copy (1992) on the World Wide Web Consortium website.
It provided an explanation of what the World Wide Web was, and how one could use a browser and set up a web server.