Ideas for World Hierarchy Example

What important things should a hierarchy of the world store? I am thinking of adding planets, continents, countries, US states, most populus cities, oceans, longest rivers, highest mountains and most spoken languages for starters. Can someone suggest other items they would find interesting? Or websites similar to http://worldatlas.com for such data? Received on Mon Jan 08 2007 - 23:43:42 CST