Loher Cashel, Stone ringfort in Iveragh Peninsula, Ireland.

Loher Cashel is a nearly circular drystone ringfort with an internal diameter of 20 m, its outer wall rebuilt to over 2 m high and 3 m thick, with terrace segments reached by stairways. Inside stand a large round house and a smaller rectangular house, and a stone-lined entrance passage with a lintel leads in.

This fortified settlement was built in the 9th century to serve as a defended farmstead in the region. Traces of earlier wooden structures show that the site was occupied and modified over time before the stone constructions were added.

Locals know the fort as Cathair an Lóthair, and the Irish word caiseal, anglicised as "cashel" or "caher", names this drystone ringfort type. The souterrain found beneath the round house floor was built after the house and is now sealed. Excavation showed the stone houses replaced earlier wooden and stone buildings.

The site is located roughly 4 kilometers northwest of Derrynane and is best explored on foot wearing appropriate shoes for uneven ground. The stone structures can be climbed and inspected closely, though the terrain requires steady footing.

The souterrain was found beneath the floor of the round house and was built after the house itself; it is now sealed. The rectangular house had a covered drain running to the fort entrance, which has a lintelled passage.