Spending a day in the south-eastern part of the Netherlands is normally enough, especially on the Pietersberg next to Maastricht they are particularly abundant (and there are a lot of other nice insects, molluscs and plants there)
The population is stable I believe but they remain restricted to the Norfolk Broads area (unlike continental individuals the British subspecies is a strict wetland specialist). With the right timing and a bit of luck with the weather they're not too hard to see (I recommend either Strumpshaw Fen or Hickling Broad for those wanting to try!).
We do get occasional vagrants of P. m. gorgonus elsewhere in southern England, but not many.
