Two earlier blogs augment today's effort:-
Traveline, Truth or Twaddle (read again)
Are You "In the Zone"? (read again)
** Before the Welsh extremists come and burn his house, fbb wishes to state that he does know that, in Welsh, "ff" is not (technically) a "double letter" but a distinct and separate letter consisting of two linked characters and pronounced "f". The Welsh letter "f" is, of course, pronounced "v". So in Welsh, Festiniog would be pronounced "Vestiniog". With that in mind, have a guess at "fandaliaeth", above.