St Teilo's Church, now a ruin, is situated within a curvilinear churchyard. The site is is thought to have early medieval origins, and to be the site of the early medieval `bishop house?, Llandeilo Llwydarth, mentioned as one of the seven bishop houses of Dyfed in a 9th century text of the Welsh laws. It has been suggested that the site is a reused concentric antenna enclosure. The churchyard may be surrounded by a concentric outer enclosure, possibly visible as a slight bank some 95m south-west of the south-western churchyard boundary. The church is some 300m south-east of Temple Druid neolithic/bronze age monument complex (NPRN 422406): a possible henge enclosure and group of late neolithic/bronze age standing stones and possible neolithic chambered tombs located to the south and south-east of Prysg Farm. This complex consists of a number of late neolithic/bronze age monuments, which lie within Temple Druid enclosure (NPRN 422403) ? thought to represent a henge. The henge may have been reused in the early medieval period, as indicated by the pesesence of 5th ?6th century inscribed stone (NPRN 304128, for approxiamte findspot see NPRN 422407). The church enclosure and Temple Druid enclosure may have been associated and formed a contemporary pair of enclosures. St Teilo's well (NPRN 32513), some 150m north-east of the church, is notable for its reputation for healing properties, the water having been drunk from part of a human skull. Two stones originally found at St Teilo's Church, Llandeilo (Llandeilo Llwydarth) 1 (NPRN 276029) and Llandeilo (Llandeilo Llwydarth) 2 (NPRN 422411) each commemorate a son of Cavetus (Andagellus and Curcagnus), while Maenclochog 1 (NPRN 276029), originally located at a findspot (NPRN 422407) some 450m north of the church, at Temple Druid (within the confines of the Temple Druid enclosure), appears to commemorate a member of the next generation, the son of Andagellus.

The church site was abandoned sometime after 1833 and the building fell into ruins.

Sources include:
Dyfed Archaeological Trust, 2003, Early Medieval Ecclesiastical Sites Project, Pembrokeshire gazetteer
Edwards, N. 2007, Corpus of Early Medieval Inscribed Stones and Stone Sculpture in Wales

N Vousden, 19 December 2017