This 12th century castle is situated 3km east of Lorrha. It was at Lackeen Castle that the Lorrha Missal was found during restoration work at the castle in the 18th century.
An illuminated manuscript written mainly in Latin with some Gaelic in the late eighth or early ninth century, it was annotated and some pages rewritten at Lorrha Monastery some time in the mid-11th century. It is also known as the Stowe Missal as it once belonged to the Stowe manuscripts collection. The manuscripts is now held in the Royal Irish Academy in Dublin.