sentences:  Mass rock
  
  A Mass rock ("Carraig an Aifrinn" in Irish) was a rock used as an altar in mid-17th century Ireland as a location for Roman Catholic Mass.Isolated locations were sought to hold religious ceremonies, as observing the Catholic Mass was a matter of difficulty and danger at the time as a result of both Cromwell's campaign against the Irish, and the Penal Law of 1695.