Knockfierna comes from Cnoc Fírinne "the hill of Truth". It stands at a height of 948 feet above sea level. Donn Fírinne was the Fairy King that gave the place its name, Donn Fírinne was believed to be a Celtic God of death or the other world.

There is a large ring fort on the Strickeen called Lios na bhFiann. On the northern slopes of Knockfierna is a megalithic tomb or dolman, locally called "Giant Fawha's grave". Its capping stone is gone and its end and side stones are, for the most part, inclined or fallen. On the hill's summit are the remains of a cairn, a monument to some forgotten chief.

There is a Mass Rock there called Carraig an Airfrinn. It dates back to the early 1700's and the Penal Laws. There are new walkways constructed around it where Mass is celebrated on occasions.

Knockfierna was a commonage where people sought refuge during the famine when they were evicted from their homes.

The Ballingarry Ogham Stone was discovered at the side of Knockfierna Hill in 1837.

Once the home of the rare yellow foxglove, the hill plays hosts to many species of flora, including tormentil, sorrel, heathers, foxglove, St. John's Wort and woodbine.

The foundations of 40 out of 200 primitive stone shacks have remained in place on Knockfierna since it was almost deserted in 1847. The 8ft by 8ft (approx.) buildings are spread over 200 acres of land. The houses, comprising of dry stone walls, clay floors, stonebased fireplaces and peat sods for the roofs, were sparsely furnished. A single bed of straw often sufficed for the entire family. The hill was densely populated, with 130 occupied homes before the famine. The houses are being gradually restored.

A 36-ft. high cross, erected in the Holy Year of 1950, adorns the top of the hill where, having enjoyed the walk up to it, there is a beautiful view of the surrounding countryside to be had.