An estimated 1,000 people descended on the North Norfolk coast after a rare bird was spotted in the sand dunes.
Within hours of the citril finch being discovered in Burnham Overy on Sunday, 500 people were on the beach.
Normally Citril Finches are found in alpine areas of Europe so the sighting of this male bird proved to be a big draw for bird watchers from across the country.
This is the first sighting of a citril finch in mainland Britain.
The RSPB’s area manager Rob Lucking estimates that the 1,000 people visited the Titchwell reserve during Sunday and Monday.
He said: “It caused a lot of excitement.
“I have seen one in France but never thought I would see on in Norfolk.
“Within a few minutes of the bird being found, the news had gone all over the country. Within a couple of hours, about 500 people were there.”
Another rare species is currently staying at the reserve.
A flock of dotterills, a wading species normally found in the Scottish mountains, are in Titchwell.
Mr Lucking said: “North Norfolk is such a good place for bird watching that we get a lot of bird watchers. The more you have, the more likely to find rare birds.
“We know that a lot of visitors to Titchwell are here on holiday and contributing to the local economy.”