A new permanent rock trap is to be installed to safeguard against rock falls at Edinburgh Castle.
Work will begin on Monday to install the new structure which will replace a temporary barrier put in place in mid-2013.
The new structure will be a one metre high stone boundary wall with 1.5 metre high metal railings on top.
The current structure is three metres high but authorities said that the loss of height will be compensated for by increasing the wall’s distance from the base of the rock, creating a rock trap and gravel blanket at the base of the castle.
New heritage body Historic Environment Scotland is collaborating with the city of Edinburgh Council to install it.
Barbara Cummins, director of heritage management for Historic Environment Scotland, who manage Edinburgh Castle, said: “It’s important that the public are assured that we have no immediate concerns regarding the rock face, however as impenetrable as the castle rock might appear, it’s not immune to the effects of the weather.
“The constant freeze and thaw during the winter months can open up cracks in the rock face, which then allows a plant known as valerian to take root. Once this germinates the bulb expands and, over long periods of time, this process can cause rocks to fracture and fall.
“At the moment we have a temporary structure in place which offers significant protection, and we supplement that by having our highly trained staff abseil down the rock on a regular basis to carefully remove loose fragments from the surface.
“Whilst these measures help to minimise the risk of rock falls, the regular monitoring and scaling is time consuming and ultimately disruptive to visitors to the castle and drivers on Johnston Terrace, which has to be closed whilst work is being carried out. The new rock trap will enhance our current risk control arrangements and reduce disruption in the process.”
The work is due to be completed in March 2016.
There will be some disruption to traffic and parking on the lower section of Johnston Terrace while the work is carried out.