The RCAHMS Gateway page provides access to the following databases relating to Scotland's built heritage:
Canmore: The RCAHMS database containing details on approximately 250,000 archaeological sites, monuments, buildings and maritime sites in Scotland. Users must register to gain access.
PASTMAP: A map enabled query system for Scottish National Archaeological and Architectural Datasets. Brings together Canmore, Scheduled Ancient Monuments, and Listed Buildings. Updated every two weeks.
HLAMAP: Provides access to info provided gathered by the Historic Land-use Assessment Project (HLA), a joint project with Historic Scotland, which is creating a digital map of the historical landscape of Scotland. HLAMAP allows the user to view the data by Historic Land-use Type, Period or Category as well as by Relict Period, and to print out a report of any selected area. National Collection of Aerial Photography: Provides access to imagery declassified by the UK Ministry of Defence, released by the Ordnance Survey, commissioned by the Scottish Government and sourced from a number of aerial survey companies. It also holds imagery from the RCAHMS Aerial Survey programme. In addition to the Aerial Reconnaissance Archives (TARA) - millions of military reconnaissance images of locations throughout the world declassified by the UK Ministry of Defence. Scran: More than 360,000 digital resources for studying heritage and material culture. The resources include images, video clips, podcasts and Pathfinder teaching packs linked to both the Scottish and English curriculum frameworks.
Variety of image formats.
Freely available data on internet. Registration may be required for some content. Full ('Zoomable') access to National Collection of Aerial Photography is by individual subscription (http://ncap.org.uk/products-services/subscriptions).