More than 90 firefighters battled a major blaze in Ashdown Forest yesterday.
Eight fire crews from East Sussex and three from West Sussex fought the fire at the Mid Sussex beauty spot.
A member of the public called to say the blaze had broken out around a car park near Forest Row, near East Grinstead.
An area of three hectares was affected.
An East Sussex Fire Brigade spokeswoman said: "It was originally reported as three hectares but it spread. It was a major fire.
"We still do not know how the fire began. It's too early to link it with the hot weather."
The forest was opened to the public a month ago following closure because of the foot-and-mouth crisis.
The Llama farm and stables in the forest were unaffected and wild deer which roam the land fled.
Leading Firefighter Time Wheeler, of Horsham fire brigade, said: "It was a rapidly growing fire and we had several changes of wind direction which made it difficult to control.
"It was a huge scale of fire particularly for this time of year and after all the wet weather we have had. The ground there was still quite wet."
Dan Pennington, a forest ranger with the Ashdown Forest Conservators, said: "The vegetation which was consumed in the fire will regenerate eventually. I expect the grass will begin to grow in about three weeks."
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