Offaly Castles Project
For details on all 200 castle sites in Offaly see www.archaeology.ie - click on Archaeological Survey Database (bottom left of screen) and you can search by location or monument type.
There has been collaberative work over the past number of years between the Department of Culture, Heritage and the Gaeltacht and the Heritage Office doing further research on the castles of County Offaly. Two pdfs on Ballindarra and Ballyboy castles are available below.
Ballindarra Castle Co Offaly
Ballyboy Castle, Co. Offaly