Located one and three-quarter miles south-east of Abergorlech, marked as Marchoglwyn -fawr and -fach on Colby’s Map of 1831.

The first-known family there were the Lloyds descended from Tewdwr Mawr. In the 16th century Thomas Lloyd of Marchoglwyn married Elizabeth daughter of William Morgan Griffith of Newton (Dynevor) by Margaret daughter of John Rees of Crug, and was succeeded by his son William Lloyd who had two sons, Thomas Lloyd of Talychlaian, and David Lloyd of Marchoglwyn who married a daughter of David Williams of Brynhafod by Anne Bryncir of Caerns. After this it became a farm, owned by various people.

In the 18th century the owner-occupier was Thomas Williams, gent., who married Mary eldest daughter of John Price gent., and by the pre-nuptial settlement dated 7 August 1733 Marchoglwyn was settled to the uses of the marriage. They had three sons and three daughters, and on the death of the first and second sons, Marchoglwyn passed to the third son Henry Williams. Henry died in 1795 leaving two sons, Thomas Williams who died unmarried in 1798, and William Williams, captain in the 60th Foot, who became sole heir.

In 1806 the captain was living at Soho, London, and in December of that year sold Marchoglwyn to Henry Davies, gent., of Wenallt, Llanfairarybryn.

Henry Davies came to Marchoglwyn and died in 1818, leaving by wife Ann Davies of Penallt near Kidwelly, four sons - David Davies who inherited Marchoglwyn, and died without issue in March 1844, Roderick Davies of Llandeilo, tiler, Henry Davies of Tirlan, Cross Hands, and William Davies who married Rachel Glasbrook and had two children.

On 23 November 1844, Roderick Davies, Henry Davies, Daniel Griffiths, and their wives sold Marchoglwynfawr to John Williams of Llandeilo, druggist, for £855.

The tithe schedule for 1839, records the following - Marchoglwyn -fawr, 84 acres, David Davies owner-occupier; -fach 32 acres, William Chambers owner; ganol 27 acres, John Williams owner.

A sale catalogue of 1920, describes Marchoglwyn fawr, 72 acres, as containing entrance passage, parlour, kitchen, back-kitchen, dairy, and three bedrooms, and outbuildings; one of the fields was called Cae Bieting, meaning the peat field.

Francis Jones in his book, Historic Carmarthenshire Homes and their Families, wrote that he could well recall in his younger days on his grandfather’s farm in Pembrokeshire, little heaps of peat being burnt in the fields and the ashes scattered over the land as a fertiliser, an operation called ‘llosci bietin’.

When Francis Jones saw Marchoglwyn it was derelict.