Idiot of The Day

[Sundae]

Now, see, you're making me learn things as well.

As an afterward, Blenheim was fairly local to me, so I probably heard the name before I ever saw it written down.
And I reiterate I am not an insufferable snob who laughs at people who get names wrong. I've done it enough times - especially once I moved out of Bucks.
Try getting your head around Mytholmroyd for example - although it's reasonably logical in the end.

And don't even think about place names in Wales...