Pretty much where it all began. In an attempt to get my head round the New Forest for a book I was planning to write, I plotted the number of places listed in the gazetteer section of Terry Heathcote's excellent Discovering the New Forest - A Complete Guide on a map.
Then I thought "Wouldn't it be nice if I could click on the map and bring up the details…". The rest, as they say, is history.
(Or was it double Geography; I can't remember now).