Site Maps, Are site maps always necessary

[Avilench]

It is my belief that if navigation is set up correctly, or well, there should not be a requirement for a separate ""site map"" page to direct the search engines spiders. If the home page contains a link to every major subsection and each subsection's main page contains links to all lower level pages and finally every page contains a link back to the home page -- boy this is a long sentence -- then no ""site map"" should be necessary.

Yet I read again and again SEO experts extolling the virtues and requirements for ""site maps"". Am I missing something?

[Sangeeta1]

As you said that without sitemaps and using proper navigations in your website you can visit to each and everypage of that site its true but its not true when we talk about the search engines.
" Most search engines will only follow a finite number of links from a page, so if a site is very large, the site map may be required so that search engines and visitors can access all content on the site".