I have a feeling Jakob Nielsen may balk at this design but I like it all the same.
When you go to the University of Cambridge’s Research section you’ll be greeted with this menu in the sidebar:
Pretty standard fair. But click on any link under Research at Cambridge…
and you get something that looks like the fair-headed child of a menu and breadcrumbs. The pages higher in the menu hierarchy have upward pointing arrows signalling “click me for a higher-level view” while also having a downward pointing nub that invites the user to drill deeper.