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:
The Basilica of Santa Maria in Trastevere is one of the oldest churches of Rome. The basic floor plan and wall structure of the church date back to the 340s, and much of the structure to 1140-43. The first sanctuary was built in 221 and 227 by Pope Callixtus I and later completed by Pope Julius I.
The inscription on the episcopal throne states that this is the first church in Rome dedicated to Mary, mother of Jesus, although some claim that privilege belongs to the Basilica di Santa Maria Maggiore. A Christian house-church was founded here about 220 by Pope Saint Callixtus I (217-222) on the site of the Taberna meritoria, a refuge for retired soldiers. The area was made available for Christian use by Emperor Alexander Severus when he settled a dispute between the Christians and tavern-keepers.
The church underwent two restorations in the fifth and eighth centuries and in 1140-43 it was re-erected on its old foundations under Pope Innocent II.