The parish church of Saint Tanwg at Llandanwg is situated just behind the beach in the sand dunes just 20 metres above the high tide mark. The church is medieval, probably dating from the 13th century, however there are three 5th to 6th century inscribed stones and two stones with inscribed crosses inside the building which indicates much earlier activity. It has probably been a place of worship since the Age of the Saints, possibly as early as the first part of the 5th century. Much of the churchyard is buried in sand. The churchyard contains the war graves of a Royal Welsh Fusiliers soldier and Royal Garrison Artillery officer of World War I.
References:Saint-Georges de Boscherville Abbey is a former Benedictine abbey. It was founded in about 1113 by Guillaume de Tancarville on the site of an earlier establishment of secular canons and settled by monks from the Abbey of Saint-Evroul. The abbey church made of Caumont stone was erected from 1113 to 1140. The Norman builders aimed to have very well-lit naves and they did this by means of tall, large windows, initially made possible by a wooden ceiling, which prevented uplift, although this was replaced by a Gothic vault in the 13th century. The chapter room was built after the abbey church and dates from the last quarter of the 12th century.
The arrival of the Maurist monks in 1659, after the disasters of the Wars of Religion, helped to get the abbey back on a firmer spiritual, architectural and economic footing. They erected a large monastic building one wing of which fitted tightly around the chapter house (which was otherwise left as it was).