My Photoshop Classroom

For most websites, navigation is not particularly challenging. A primary navigation bar, supported by sub-navigation, is often enough.
Typically, sub-navigation displays the parent, siblings and children of the current page. A persistent primary navigation bar shows top-level pages, allowing users to move between sections.
However, there is one class of website for which this traditional form of navigation falls short. It is what I refer to as a “mega-site”.


Source: http://www.smashingmagazine.com/2013/03/27/navigation-mega-sites/