A digital mapping resource is being developed which allows the user to compare maps of Londonderry for different time periods. It includes Thomas Raven’s map of 1622 which was surveyed just prior to the compilation of the Great Parchment Book.

The Digital Atlas of Derry~Londonderry is a collaboration between the Royal Irish Academy, Derry City Council and The School of Geography, Archaeology & Palaeoecology at Queen’s University Belfast.

Based on the Irish Historic Towns Atlas, no. 15, Derry~Londonderry by Avril Thomas (Royal Irish Academy, Dublin, 2005), the Digital Atlas provides users with historical and topographical information about the city of Derry for selected time-periods. The key map is a reconstruction of the city in 1831, which is presented in an interactive way. Streets, buildings, city walls/gates and public buildings are mapped and further detail such as name, dates and other historical information is provided in pop-up boxes.

As well as the 1831 map, earlier and later historical maps, including Raven’s 1622 map, can be overlaid and compared. The different map layers reveal not only the way the city developed, but also the way that mapping evolved since the walled city was founded in the 17th century.

This web-GIS resource is still at an experimental stage, but is worth taking a look at.