User Guidelines

The Leo Swan Archive was bequeathed to the National Museum of Ireland, who retain the rights to the collection.  Images on this site are made available by the Discovery Programme under a Creative Commons Non-Commercial No-Derivatives 4.0 International licence (CC BY-NC-ND 4.0). For any use of images which falls outside of the license parameters (e.g. commercial use, publication), please contact the Discovery Programme.

All of the photographs in the archive are presumed to have been taken by Leo Swan. Every effort has been made to reproduce the entirety of the archive but in some cases photographs have been excluded where the original film produced unsuitable digital copies or where photos were not related to the purpose of the online archive.

This website is a work in progress, we are continuing to develop and update both the metadata and functionality of the site. If you encounter any problems or can supply further information about any of the photographs we welcome your feedback, please contact us


Metadata development is ongoing and will be updated with additional information in the future. This will include the Sites and Monuments Record (SMR) number where applicable.

Each set of film was assigned a unique filename based on the type of film, with a frame number appended to the end. For example, the file name ‘LS_AS_35BWN_00002_05’ indicates that this image is from the 5th frame in a 35mm black and white film, which was given the set number ‘00002’.

A gap in frame numbers in a set does not necessarily indicate a frame is missing, but as the archive was used for research and publication throughout Leo’s career, some frames have inevitably been lost or are located elsewhere. We welcome any additional information on possible additions to the archive, please contact The Discovery Programme.

Search & Browse

The online archive can be browsed via items or by the paginated map. If searching for particular areas or sites we recommend searching by townland name. These are taken from the National Monuments Service’s Historic Environment Viewer and are based on the townland names given by the OSi MapGenie mapping service. Please refer to the Historic Environment Viewer in order to ensure the correct spelling and location of townlands when searching for images. This is particularly relevant when searching for well-known sites which are recorded only by the townland name, for example Tara can appear under Castletown Tara or Castleboy. In the future the site will be updated with familiar names for well-known sites but for consistency a standard system of recording townlands was used.

Please note that in Gaeltacht areas, townland names are given in Irish, as they appear in the Historic Environment Viewer.

A set of film often corresponds with a route or partial route taken by Leo Swan.  Searching the website by filename thus enhances the experience for the web user, particularly when the route follows a river or when the plane (as frequently happens with ecclesiastical enclosures) circles a site to record it from different perspectives.


The Leo Swan Aerial Archaeology Archive was digitized by the Discovery Programme as part of the LoCloud project. As with any transition between analogue and digital formats, discrepancies in colour tone, brightness and quality are unavoidable. Every effort has been made to retain the authenticity of the original image but in some cases adjustments were made using imaging software to improve the digital surrogate. This was only carried out when images were extremely dark or where inconsistencies in colour tone were observed in the scanning process.

Scanning was carried out by Louise Kennedy, Katherine Daly and Evie Monaghan on three scanners:

  • Epson Perfection V750 Pro

  • Plustek OpticFilm 8200i

  • CanonScan 9950F





Locloud is funded by the European Commission's ICT Policy Support Programme.