Fire crews have spent the night tackling a large fire at a disused RAF building near Lincoln.
At its height, about 70 firefighters attended the blaze at Nocton Hall, which started just before midnight.
The fire is now under control, but the roof has collapsed and the building is severely damaged.
A nearby nursing home, with about 27 people, was evacuated but nobody was hurt. An investigation is under way into the cause of the fire.