It came under the control of the Augustinian canons in the 12th century before being seized by the English Crown during the Reformation and gradually falling into ruin.

[5] The site is only a few kilometers from the river mouth and the natural port of Youghal on the south coast of Ireland.

[6] According to some traditions, it is known that a sea voyage in the early Christian period between the Southern coast of Ireland and Brittany could be completed in three days and nights.

[9][10] The early monastery was recorded as having an extensive library including Greek Vulgate and African councils resolutions.

The Crown report compiled in 1541 stated the monastery consisted of a church, cloister and all that was necessary for the operation of agriculture, including 380 acres of land, three weirs for catching salmon and a water mill.

The land and ruins were owned by Richard Boyle, 3rd Earl of Burlington up to the mid-eighteenth century when it passed to the Smyth family who built a nearby manor named Ballynatray House complete with a surrounding park in 1795.

The name of the island would suggest that oak trees were widely available locally so the early monastery was probably constructed of this.

[17] It is typical for this time period of construction, the preferred method was the use of fairly large stones if possible, which were carefully selected and arranged so that a relatively high degree of accuracy was achieved.

Further south was followed by other areas with the chapter house and the staircase that gave access to the dormitory on the top floor.

These include a pointed arch entrance on the north side of the old church hall, a historically incorrect statue of the founder Máel Anfaid as an Augustinian Canons Regular and a memorial plaque on the east pediment of the refectory which claims to be the burial place of Raymond Fitzgerald although it is thought he was buried elsewhere in the monastery.