It is located in the countryside above the valley of the River Tywi, about halfway between Llandovery (Welsh: Llanymddyfri) to the north-east, and Llandeilo to the south-west.

Four miles to the west of the village are the ruins of Talley Abbey (Welsh: Abaty Talyllychau).

[2] The village is also believed to be the site of an important manor, Abermarlais Castle a fortified mansion, built in about the C14 (Rees 1932), it was home to Sir Rhys ap Gruffydd who commanded the Welsh at Crécy (Jones 1987, 4).

Saint Sadwrn is a Welsh saint present: Llansadwrn cemetery has a funerary stele with a late 6th century inscription dedicated to a certain Sarurninus [close form of Saturninus] and his holy wife.

The necropolis of Saint-Urnel (also known as Saint-Saturnin, by assimilation to this saint, Saint Saturnin, recognized by the Catholic Church, but whose cult is not widespread in Brittany), corresponds to a cemetery from the early Middle Ages (from the end of the Merovingian period to the Carolingian period), vast of around ten hectares, which includes tens of thousands of skeletons buried in superimposed layers (at least five layers); located on a hillock east of "Pointe de la Torche", this vast cemetery, initially excavated by Paul du Châtellier and who made the object of other excavations in the inter-war period, corresponds, according to Pierre-Roland Giot (archeologue) who excavated it between 1946 and 195044, to that of an important parish which would have existed between the 5th century and the 11th century (it was even the seat of a deanery which was abolished in 1283 and replaced by that of Beuzec-Cap-Caval), and which would have been buried under the sand due to the advance of the dunes.