The place-name 'Bryn Henllan' (hill of the old church) indicates the presence of a former church in the vicinity. The site may be early medieval in origin. Undated cist burials have reportedly been observed in Tygwyn farmyard prior to 1981, and beneath a track between Tygwyn and Brynhenllan Chapel. The cemetery lies some 800m south-west of St Brynach's Church, Cwm-yr-Eglwys (NPRN 304400) and may have been its predecessor. Ludlow suggests that a stream running north from the boundary of Tygwyn farmstead may have possibly formed the eastern boundary of the cemetery site.

Sources include:
Dyfed Archaeological Trust, 2003, Early Medieval Ecclesiastical Sites Project, Pembrokeshire

N Vousden, 24 November 2017