The Priory Church of St Mary Magdalene is a grade II* listed building and was founded ; a Cluniac priory of St Martin-des-Champs. It is considered to have the best surviving Norman stone carving in Carmarthenshire. The church was restored in 1853–5 and in 1883–4. The stained glass is. The Norman St Clears Castle was constructed in the 12th century. The castle mound can still be seen. The town, which was a MarcherBorough, grew around it. Below the castle, there was a port on the river Tâf, which could take ships of up to 500 tons according to a plaque at the site. The castle held out against Owain Glyndŵr. Nearby Trefenty House became the home of a branch of the Perrot family in the 16th century, and it was here that the amateur astronomer Sir William Lower and a neighbour, John Protheroe, set up one of Britain's first telescopes in 1609, which they used to study the craters of the Moon and Halley's Comet. In 1842, one of the local toll gates was destroyed in the Rebecca Riots. The building of the South Wales Railway in the 1850s was responsible for the decline of many of the small ports along the Bristol Channel coast, and St Clears was no exception. The railway passed about two miles north of the castle, and new building at the north end of the High Street spread eastwards along Pentre Road, and then northwards to the station. Pentre Road is now the main commercial centre of St Clears and was formerly part of the A40 road until the bypass opened. The town's cattle market was important until its closure, but the town still has a large agricultural cooperative store. The town has also hosted an oil distribution centre and milk processing plant. Now smaller industrial units provide the main local employment. The photographer and film-maker Stanley Phillips lived in St Clears and documented life in the town and the surrounding area. His work appeared in the News Chronicle and the Daily and Sunday Mirrors, and in local newspapers. His films include The Last March of Mr. Jonah Rees at St. Clears, which is in the collection of the National Library of Wales. He worked closely with Colonel William Buckley and E.V. Williams, both keen filmmakers. The permanent exhibition of Phillips' photographs and film at the Mezzanine Gallery in St. Clears includes photographs of the aviator Amy Johnson, World War I flying ace Wing Commander Ira Jones, and racing drivers Sir Malcolm Campbell and J. G. Parry-Thomas, who both attempted world land speed records at nearby Pendine Sands.
The original railway was constructed by the South Wales Railway. Although trains travel on the West Wales Line through St Clears, they have not stopped since 1964. A local campaign group is attempting to persuade the Welsh Government and Network Rail to reopen St Clears railway station.
Amenities
The town has a large bilingual primary school, Ysgol Griffith Jones. There are a variety of local shops including two prize-winning traditional butchers and two craft centres. There are several pubs. The surrounding countryside is mainly rolling grassland consisting of moderate-sized fields with well-kept hedges. The main agricultural enterprise is dairying, but sheep and beef are very important as well. The soils are deep and productive and will grow good crops of potatoes and cereals, and the climate allows fruit growing as well. Although most of the land is farmed commercially the area is a haven for wildlife. The highlight of the farming year is the St Clears YFC annual show which is held in May.
