The King's Mirror (Speculum Regale—Konungs Skuggsjá).
Translated from the Old Norse with Introduction and Notes by Laurence Marcellus Larson (New York: Twayne Publishers, Inc., & The American-Scandinavian Foundation, 1917), pp. 108-109 (with translator's note; on Ireland):
There is another little island in that country, which the natives call Inhisgluer.† There is a large village on this island and also a church; for the population is about large enough for a parish. But when people die there, they are not buried in the earth but are set up around the church along the churchyard fence, and there they
stand like living men with their limbs all shriveled but their hair and nails unmarred. They never decay and birds never light on them. And every one who is living is able to recognize his father or grandfather and all the successive ancestors from whom he has descended.
† Inhisgluair, now Inishglory, is on the west coast of Ireland in county Mayo. Giraldus mentions the legend but assigns it to a different locality; see Opera, V, 83 and note. The Irish Nennius (193) adds that the nails and hair grow and that unsalted meat does not decay on the island. The island is also referred to in the Reliquiae Antiquae, II, 103.