The 'Holy' hour
Dublin pubs were closed by law on Sundays from 2-3pm up to quite recently. This was known as the 'Holy hour' and was the bane of every diehard drinker's life. You will still find pubs closed on Good Friday though as a mark of religious respect (or some might say a reflection of a byegone age)...
An excellent pub on Dublin's northside is Clearys on Amiens Street [see map, section R-46 and near the railway overbridge] and it was recommended by Wicklow resident and journalist Huib Zegers - many thanks Huib! He says "Although my roots are in the home of Heineken, I got converted to Guinness nearly a quarter of a century ago. I think the Guinness in Cleary's is excellent and - of importance to a Dutchman - modestly priced."
The Brazen Head on Bridge Street [see map, section J-49] is not too far from Christ Church Cathedral, Bridge Street joining the South Liffey Quays with Thomas Street. It is alleged to be Dublin's oldest existing pub and has some good traditional music sessions at the weekend. Apparently, it was a favourite haunt of Irish writers Patrick Kavanagh and Brendan Behan (I would imagine that a lot of Dublin pub could safely say that Behan was a customer of theirs!). One of the few remaining intact sections of Dublin's medieval city wall is quite near the Brazen head, as is another treasure, St Audoen's church.
For a genuine Irish bar with local Dubs try Fallons which is at the junction of the Coombe and New Row [see map, section K-52] New Row goes south from the Coombe but is not named on this map], just beside the Patrick's Street junction. The locals are very particular about their pint, both taste and price. It's almost beside St Patrick's Cathedral (you can almost see it from the door) and it's worth taking the risk of getting killed by a car to reach it. You'll find few (if any) tourists there, and the bar staff are very friendly and helpful.