More than 100 firefighters were called to tackle a grass fire covering 400 acres of land in Surrey.
Crews from the north west of the county were first alerted to the fire at West End Common in Woking just before 1300 BST.
Overall 20 fire engines went to the scene carrying 120 firefighters.
Four water carriers were also used and four off road Land Rovers.
Cause unknown
Surrey Police closed off a number of roads near to what they described as a "major fire".
Divisional Officer Kevin Reddick, from Surrey Fire Brigade said he expected fire crews to stay at the scene for at least 24 hours.
Crews from other counties including Berkshire, Hampshire and London helped douse the fire.
Mr Reddick said: "We haven't had to call anyone in off duty and we are dealing with it with the resources within the force."
A police spokeswoman said the cause of the fire was unknown at the moment.