Sliabh (anglicised in placenames as slieve) describes the mountain or high open moorland that is one of the defining landscape features of Ireland's western and northern regions. In early Irish poetry, the mountain is a place of hermit retreat, of the wild man's exile, and of visionary experience at the boundary of the human world. In later verse it is the enduring feature of the landscape that outlasts human generations and carries the weight of ancestral attachment. The great mountains — Croagh Patrick, the Reek, the Mournes — are so charged with religious and literary association that to name a sliabh in poetry is to invoke this entire tradition of sacred high ground.

Sliabh (mountain) in Irish poetry is a majestic and imposing landscape feature, symbolizing grandeur, challenge, and permanence. It is associated with hardness, isolation, and spiritual elevation. Poets use sliabh imagery to convey awe, struggle, or transcendence. Climbing a sliabh is a metaphor for overcoming difficulties or gaining perspective. The sliabh is a site of weather extremes, reflecting the unpredictability of nature. It contrasts with the gentle cnoc, offering a more rugged and sublime aesthetic.