In earlier times the townland was probably uninhabited as it consists mainly of bog and poor clay soils. It was not seized by the English during the Plantation of Ulster in 1610 or in the Cromwellian Settlement of the 1660s so some dispossessed Irish families moved there and began to clear and farm the land.
A deed by Thomas Enery dated 29 Jan 1735 includes the lands of Curraghaglass.[3]
The 1790 Cavan Carvaghs list spells the name as Corglass.[4]
The Tithe Applotment Books for 1826 list three tithepayers in the townland.[5]
The 1836 Ordnance survey Name books state- The soil is of a light blue gravelly nature...two ancient forts, one near the south end and the other near the center of the townland.
The Curraghglass Valuation Office Field books are available for August 1839.[6][7]
A medieval earthen ringfort. The ‘Archaeological Survey of County Cavan’ (Site No. 491) describes it as- Raised circular area (int. diam. 26.6m) enclosed by a low earthen bank and traces of a fosse. Perimeter has been slightly modified and incorporated into the field boundary. Original entrance not recognisable.
A medieval earthen ringfort. The ‘Archaeological Survey of County Cavan’ (Site No. 492) describes it as- Raised circular area (int. diam. 24.7m) enclosed by a substantial earthen bank and remains of a fosse. Stone field boundary has been built against the outer face of the bank at south. Original entrance not recognisable. A small stone enclosure (probably modern) projects from the bank into the interior at north.