Rhiwledyn Cave is situated on Little Ormes Head, which contains a number of similar small caves and shelters. From Little Ormes Head there is a panoramic view across a large part of north Wales, with Great Ormes Head to the west, the river Conwy to Penmaenmawr to the south-west, and the whole of the north coast to the east. The cave is located some 140m north-east of Chimney Cave (NPRN 418693), with its entrance obscured by a natural limestone curtain on the sheer north face of the Rhiwledyn Ridge. Its interior is 6m in length, with an average width of 1.75m. The height varies throughout its length. Only twenty per cent of the cave floor is soil, the remainder having a stalagmite base, over 1m thick in places. The rear of the stalagmite base has been broken through (possibly by modern potholers) to reveal a layer of thick mud sediments. The resulting hole has been cut in a series of steps, causing the deposition of material into the steps.

Rhiwledyn Cave was first identified in 1959 and was excavated from 1962-1976. The largest concentration of bones and artefacts occurred within a narrow hollow running the length of the cave, formed by the stalagmite base and the cave wall. Some 518 bones were recovered, in addition to many hundreds of frog and toad bones and more than 600 unidentifiable bone fragments. They included bones belonging to at least four humans: a four year old, an eight-nine year old, a ten-twelve year old and an adult. Humans are thought to have occupied the cave during Neolithic/Bronze Age transition (around 3,000 BCE). Other species present included fox, sheep, rabbit, wood mouse, field vole, brown rat, wild boar, roe deer, ox, small ox, cat, stoat, sheep, hare, stoat, goat, carrion crow, partridge, chough, starling, chaffinch, herring gull razorbill, rock/stock dove, pipit, partridge, domestic fowl, turkey, cormorant and guillemot. This range of mammals is represented by species that would have naturally sought refuge in the cave, species brought in by predators, and butchered remains brought in by humans. Butchered bones derived from sheep, ox and small ox. It is thought that the ox was butchered with a metal axe. The phalanx of a young sheep was found to have a small hole pierced in its lateral face. Artefact finds include an amber bead, three discoidal pebbles, a spherical pebble, two slate tools and an antler tool.

Sources include:
Blore, J, 2012, Archaeological Excavation at North Face Cave, Little Ormes Head, Gwynedd 1962-1976

N Vousden, RCAHMW, 26 March 2013