Have you ever looked at the Table of Contents of a
book and been unable to find what you wanted? Of course.
So you
went to the Index.
It's for that same reason that every
site, no matter how obvious the
designer feels
it is,
should have a site map. It's a different way for users
to navigate and access the site. It accommodates the
different ways that users
approach the organization of a site or think about its
content.