Immediately to the south east of Fortrose's narrow High Street is the surprisingly spacious Cathedral Square, home to the red stone remains of Fortrose Cathedral.
The site was chosen for a new Cathedral of Ross by Bishop Robert to replace the Church of St Peter in nearby Rosemarkie. This followed permission granted in 1236 by Pope Gregory IX, reaffirmed in the 1250s by Pope Alexander IV. The cathedral was probably finished by 1300 as a fairly simple structure some 185ft long and 25ft wide. The 1400s saw additions made in the form of a south aisle and chapel, plus a tower.
https://www.undiscoveredscotland.co.uk/fortrose/fortrosecathedral/index.html