I think we're all intimately familiar with the primary navigation for a website - that which is usually front and centre, some form of which is on every page of your site, commanding the attention of the user. It's the most important part of your website, the list of links your users will use to wend their way through your site. The primary navigation has to be straightforward, easy to use and consistent throughout your site.
You can also navigate a site through a secondary means - the site-search function, if the site owner has provided one. When the user can't find the link path to the information they are seeking, a site-search box can be very helpful. Type in the search term and off they go.
At UNB we've gone an extra step by providing a tertiary means of navigation - the buffer page. Which is basically a page sitting on our corporate url and pointing to complementary or parallel programs/departments on our campus-specific urls. This type of navigation is aimed at those "in the know", users who are familiar with university sites in general and know that most universities have similar departments or offer similar programs. Since UNB is a multi-campus institution, our thinking was that some users who were familiar with university systems and web savvy as well, might just type in a department name in the location bar of their browser, rather than learn the navigation system. We developed buffer pages at our corporate root url to accomodate for those departments who have counterparts on either campus because we also wanted to make sure that users to our site, on landing at a page under the corporate url, be informed that there may be parallel programs or departments on either campus and they could investigate which campus then best suits their needs.
Here are some examples:
