The Ruined Castle bushfire has moved into the Megalong Valley after crossing Narrow Neck Plateau overnight (Tuesday, December 10).
"Fire yesterday moved onto the Narrow Neck Plateau and despite the best efforts of firefighters last night it burnt into the Megalong Valley," the Rural Fire Service posted on Wednesday morning.
"Firefighters will look to conduct a backburn on the western side of the Narrow Neck Escarpment to stop the fire further spreading into the Megalong Valley."
Narrow Neck and Glenraphael Drive are closed.
The fire is still at advice level, with the RFS advising people in the area of Cliff Drive at Katoomba and in the Megalong Valley to monitor conditions.
Blue Mountains mayor Mark Greenhill said emergency services agencies were well prepared for this eventuality. He attended a regular fire briefing on Wednesday morning with Federal Member for Macquarie Susan Templeman.
"What stands out is how well the agencies had prepared for this and how ready they are to manage it," he said.
"I feel very confident in the strategic work that has been done and I am impressed with how seamlessly all the different agencies are working together in the Blue Mountains.
"Of course, all of this has been underpinned by our volunteers on the ground. They have been working incredibly hard for our community. They must be so tired. I have the deepest respect for them all."
For updates visit Fires Near Me.