It was an accidental and fortuitous road that led me to finding the ancestral Riordan farm in Co Limerick, Ireland. I was really looking for the birth/baptism/ any evidence of my great-grandfather, Patrick Riordan.
1) Pre-knowledge: From Patrick's death registration, I knew his parents were John Riordan and Bridget Quane, and that he was born in Curraheen, Co Limerick.
2) Wrong assumption: I assumed from a list of townlands, that this Curraheen was up near the River Shannon- but it seemed odd even then, as it was so far from Glenroe where O'Donnell priest-cousins were known to come from.
3) Parish registers online: When the parish registers came online -thanks NLI- I searched this area diligently. Not many likely looking names at all- distinct lack of Riordan, Quane, O'Donnell, Malone families. Hmmmm.
4) Google is my friend: Plugged in "Riordan Quane Curraheen". Bingo! Turned up entry in 1829 tithe applotment books for Curraheen. There was a widow Riordan, and a John Quane. This Curraheen was in Ballylanders Parish, and it was significantly close to Glenroe.
5) Searched Ballylanders Parish register: Found two births to John Riordan and Bridget Quane- Ellen (June 1850) and Bidy (Jan 1855). This register transcript started from 1849, and I never found my Patrick- but I was sure I had the right parish.
6) Turned to Google again: Bingo again- hugely significant find! Found a census extract from 1916 for a James Riordan from Ballylanders Parish. This would have been used to find evidence of date of birth from 1841 census to obtain the old age pension. Official had written in names of parents- John Riordan and Bridget Quane- and listed the siblings down the side- Margaret, Patrick, Mary, Ellen, John and Bridget. Finally evidence of my Patrick... It also listed the Parish- Ballylanders, and the townland- Cullane South.
7) No Curraheen? Hmmm. There was a Curraheen in 1829 tithe applotment books in Ballylanders Parish. But by the time of Griffiths Valuations it seems to have changed its name to Cullane- North, South... Same parish, but a Cullane instead of a Curraheen...
8) John Grenham to the rescue: Google again- this time looking for a map of Cullane South. Found invaluable links on John Grenham's site. It led to...
9) Griffiths Valuations: I can't give you the link here as it is time-limited one to askaboutireland.com But use Grenham's Cullane South link to take you to a list of Occupants, and a map... John Riordan is farming there and section 20 is the land. Use the slider on the map and you can alternate between modern and old maps. (And there is a Carheen Fort on the edge of the Riordan land as it happens...)