Restoration work on the royal palace at Stirling Castle is under way.
Historic Scotland said the £12m makeover will see the palace's royal lodgings refurbished, and new facilities installed.
The lodgings, which would have accommodated Mary of Guise and her daughter, Mary Queen of Scots, date from the 1530s.
The work is being done by Morris & Spottiswood, who said a helicopter may be needed to transport materials in.
The lodgings are on the ground floor of the royal palace, which is thought to be the last intact Renaissance-era palace in the UK.
The restoration project will involve work on all areas of the palace and the old chapel, including the palace vaults where there will be an interpretative display of the court of James V.
It will also see a Renaissance-style gallery created on the upper floors of the palace, which will house the original Stirling Heads - a rare group of carved oak ceiling medallions depicting kings, queens, courtiers and mythological creatures.
Morris & Spottiswood said it had secured a £4.8m contract to carry out three sections of the work.
Business unit head Tony Ward said: "This is a site of great historical importance and therefore a very prestigious project to be involved in.
"In addition, there are several challenges which make it a very interesting project.
"We are investigating, for example, using a helicopter for movement of the materials because the entrance to the castle doesn't allow for large heavy vehicles or cranes.
"All the steelworks therefore need to be connected and constructed on site and the scaffolding will need to be specially designed because of the crag-top location of the castle."
The work is being completed thanks to a £9m investment from Historic Scotland and £3m from the Scottish Government.
The palace will be closed until 2011, when the work is due to be completed.