Transport chiefs leading the ambitious A9 dualling project have pledged to spend about £500,000 on archaeological work to protect historic sites in Perthshire.
An extensive survey of the Luncarty to Pass of Birnam stretch will be carried out before construction.
The area contains several standing stones and the Court Hill Cairn, an ancient scheduled monument.
There is also the Perth to Dunkeld turnpike, a construction which dates back to 18th century when people were tolled for using the road. The site of a now demolished toll cottage has been identified.
Aerial photography of the six-mile stretch suggests there is evidence of further prehistoric activity, with the potential for more hidden remains.
Transport Scotland is now looking to take on a contractor to carry out archaeological work along the route.
Companies have been invited to bid for the contract, which is worth an estimated £470,000.
The brief to bidders states: “The main objective to be delivered by the economic operator will be evaluate or mitigate the effect of the scheme on cultural heritage assets.
“This will require non-invasive and invasive archaeological investigations, mitigation excavations if required, and post-excavation assessment and reporting.”
A search was carried out further north at the site of the 1689 Killiecrankie battle.
The survery unearthed, amongst others, a copper alloy pendant, horse shoes, buttons and musket munitions.
A Transport Scotland spokesman said: “It is standard practice for us to consider the impacts of all major road infrastructure projects on cultural heritage prior to any works starting on site.
“This involves undertaking archaeological surveys to ensure that any potential archaeological assets are carefully recorded to preserve Scotland’s cultural heritage.”
He added: “As is usual for projects of this nature, and following initial surveys across the A9 Luncarty to Pass of Birnam scheme, a number of potential archaeological assets have been identified as requiring further investigation to determine the existence and extent of any buried archaeology.”
Meanwhile, further work on the £3 billion dualling project will get under way next month after contracts for two ground investigation were awarded.
BAM Ritchies will undertake the contract totalling nearly £3 million for the Crubenmore to Kincraig stretch.
And Raeburn Drilling & Geotechnical Ltd will also undertake the contract totalling approximately £3.8 million for the Pitlochry to Glen Garry stretch.
Keith Brown, cabinet secretary for economy, jobs and fair work said: “Over the next few months some of this work will take place on or near the live carriageway. In order to ensure the safety of both road workers and road users we will need to introduce traffic management arrangements.
“Road users and local communities will be kept informed of our plans and we will endeavour to ensure that any disruption is kept to a minimum, recognising that there are on-going construction works between Kincraig and Dalraddy.”
