National Records of Scotland has released to Scotlands People “more than 2,400 historic maps, plans and drawings” that show country estates and plans of towns and cities.
See News Article: Maps and Plans Release (June 13, 2018).
Spanning four centuries, the collections cover both manuscript and printed topographical maps and plans. They are particularly strong in estate and railway plans; architectural drawings; and engineering drawings, particularly of ships, railway engines and rolling stock. More maps and plans will be added to the ScotlandsPeople website.
Requires free registration at Scotlands People to access and search
A search on Atholl delivers “Plan of the estates of Fincastle, Borenich, Lick and Duntaulich, Blair Atholl” (RPH6594). Dated 1832, this map shows the lands along the Tummel River.
Speaking of Scottish resources, Ancestral Findings offers this list of Online Resources for Researching Your Scottish Ancestors. Scotlands People and five others (including Family Search) are described here, and there are links to other postings related to Scotland.