This church is built on the site of St. John's hospital, there used to be a huge tower about eight feet high. It dates back to 1181 but it had to be demolished around the 1800's as it become unsafe.
The Augustinian Friars came to Dublin from England. Their original friary used to be outside the walls of the city. When the bully Henry VIII suppressed all religious places, the Augustinians decided to stay on disguised as teachers or doctors to attend to the needs of people secretly.
Once the oppressed years of Henry VIII rule passed, the congregation grew and they had to build according. The result is this huge building with exquisite stained glassed windows and statues which have a lot of history themselves.
You can just walk in of the street and investigate yourself. There is a lot of information available regarding the history of the building. read more