Old St Peter's Kirk is the most atmospheric historic sight in Thurso: a roofless medieval church and burial ground near the river and seafront. Historic Environment Scotland records the church as 13th century at the latest, with links to the Bishops of Caithness and later additions from the post-Reformation period.
It is not manicured into a museum piece, which is part of the appeal. The stone walls, burial ground, blocked arches, and town around it give a clear sense of how old Thurso is beneath the ferry traffic and modern shops.