It is believed that Saint Domangard or Donard founded a monastery in Maghera in the early christian period, c. 500 AD. He lived as a hermit on Slieve Donard, a nearby mountain that is named after him. There are no antiquities remaining from the early foundation but excavations in 1965 produced evidence of occupation around the tower during the Early Christian period. The medieval church situated behind the more modern church probably dates to the 12th century. It is much harder to date the round tower as there are no features such as windows or doors that normally help in dating round towers.
The tower, which is built from rough uncoursed granite field-stones similar to the tower at Castledermot, is believed to have fallen in the 18th century as a result of storm damage. All we see today is a 5.4 metre high stump with a large breech on the eastern side of the tower. This may represent the position of the doorway, suggesting a rather low entrance. The diameter of the tower at base level is 4.85 metres. The stones used in the building of the tower suggest a 10th century date but is not definite proof.
References:The Temple of Edfu is one of the best preserved ancient shrines in Egypt. It was built in the Ptolemaic Kingdom between 237 and 57 BC.
Edfu was one of several temples built during the Ptolemaic Kingdom, including the Dendera Temple complex, Esna, the Temple of Kom Ombo, and Philae. Its size reflects the relative prosperity of the time. The present temple initially consisted of a pillared hall, two transverse halls, and a barque sanctuary surrounded by chapels. The building was started during the reign of Ptolemy III Euergetes and completed in 57 BC under Ptolemy XII Auletes. It was built on the site of an earlier, smaller temple also dedicated to Horus, although the previous structure was oriented east–west rather than north–south as in the present site.