More details have emerged about Highland Council’s plans to open up Inverness Castle as a tourist attraction.
Public viewing areas are proposed for the North Tower, offering panoramic views of the city and surrounding countryside.
The £360,000 project has won widespread support and it is hoped it could be open in time for next year’s tourist season.
The council’s application for listed building consent is being examined by its planning department but documents submitted as part of the process have revealed new details about the plans.
Engineers had considered putting a spiral staircase inside the tower’s slimmest turret however this option has been dropped because the structure is too narrow.
Another option was to remove the roof of the larger main turret and install a stair below the parapet in order to retain views of the castle.
The preferred option is a spiral staircase inside the main turret and breaking through the roof.
A glass structure, with a door, would be built around the staircase to protect it from the weather.
A second spiral stair will be installed allowing access to another viewing platform.
Glazed balustrades, with metal handrails, will also be installed along the platforms as part of safety arrangements.
Because of the building’s age, Historic Scotland is being consulted on the plans.
Last month Highland councillors approved a £100,000 funding request towards the project. Other funding will come from Highlands and Islands Enterprise.
A business plan prepared by High Life Highland, which would operate the platform, predicts that 26,500 visitors each year in a season stretching between Easter and October, with adults being charged £2.50 and children £1 for access.
The castle incorporates the city’s courthouse. A feasibility study is under way into options for the building if the Scottish Court Service moves elsewhere in Inverness.