Sometimes I just like to meander through Wikipedia. A while back I did this and found myself going around circles. My route was as follows:
Sapir-Whorf hypothesis
The eleven basic colour names in English
The history of the crayola company
Prussian blue
Prussia
The first world war
Warfare
Christopher Columbus
Leif Ericson
Newfoundland
World's largest islands
Devon Island
Hypolith
Cyanobacteria
Cyanide
Prussian blue (again)