One thing leads to another. The post on a congregation of cownose rays led to an exploration of venereal words. That prompted Tess to compile a list, which made MW wonder about the etymology of "Watership Down." So... this morning I look up Watership Down, and am reminded of Fiver and Hazel and Bigwig, and (forcing myself back to the quest) find that a downland is an area of open chalk hills.
The word "down" itself comes from an Old Germanic or Norse word "dun," meaning "hill." Which naturally brought to mind the famous Torpenhow Hill. It's in Cumbria and is famous because of the tautology of its name - derived from the Saxon "tor," (meaning "hill"), Celtic "pen," (meaning "hill"), Scandinavian "how," (take a guess...), and Middle English "hill."
Which reminds me of the Aruwimi River in the Belgian Congo, named by David Livingstone. He inquired of a native, “What is the name of this river?” The answer was “Aruwimi,” meaning “What is this fellow saying?”
And the search eventually leads on to - where else? - Wikipedia, which has a jaw-dropping list of tautological place names. At the end of which one is lured into "pleonasm".
But I have to get on to my morning surfing....