A large area of Norfolk reed and dried grass, between the Gaywood River and Queen Elizabeth Hospital, caught light this afternoon.
At the height of the fire, the large plume of smoke could be seen from the A10 as far south as Tottenhill.
Three pumps from King's Lynn and Sandringham were sent to tackle the blaze, after the alarm was raised at 12.30pm.
They could access the scene from the A149 Queen Elizabeth Way, but pumps could not get across soft ground around the burning reed.
Firefighters used backpack sprayers to tackle the flames.
Clouds of smoke were blowing across the grounds of the Queen Elizabeth Hospital, a few hundred yards from the fire.
'The fire to the rear of the hospital grounds is not affecting our services,' a spokesman said. 'Staff have been alerted as a precaution.'
It is not known how the blaze started, but firefighters tackled a fire at the same scene on Saturday.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here