There's a new website with the aim of "bringing authentic information and images together to help you discover places in Scotland."
The ScotlandsPlaces website www.scotlandsplaces.gov.uk "lets users search across different national databases using geographic location. The user is able to enter a place-name or a coordinate to search across these collections or they can use the maps to refine and define their search."
Included are digital copies of:
Maps and plans of cities, towns, villages, farms, roads, canals, harbours, churches, schools, public buildings, private houses, mines and quarries
Photographs of the built environment in The Royal Commission on the Ancient and Historical Monuments of Scotland
Archaeological reports on historic and prehistoric sites
A search for Ayr, yielded the description "A parish in Ayrshire until 1975. The parish of Alloway was annexed into Ayr in 1690. The parishes of Newton-upon-Ayr and St Quivox were annexed into Ayr in 1895. It was a parish for both civil and religious purposes from the sixteenth century until 1975. The boundaries of the civil parish were altered by the Boundary Commissioners in 1891."
There was a map which you could click to refine the search, and 501 hits. Worth a look if you have Scottish ancestry.