The earliest of the Christian Imrama that we possess is _The Voyage of Maelduin’s Curach_, the composition of which Professor Zimmer refers to the eighth century at latest, though it contains interpolations which Mr. Nutt considers to have been made at the end of the tenth century.[131] It relates a voyage undertaken by Maelduin, a young noble of the Eoghanachta, in order to find the murderer of his father who had been slain by a marauder of Leix. The tale is a remarkably fine one of its kind, and its simple and picturesque prose is by no means improved upon by Tennyson’s poem, the subject of which it suggested. It is long, and contains a great variety of incidents, some of which, it is very possible, may not belong to the original Celtic stock, but may be due to classical sources. Certain it is that a great part of them belong to that class of ‘ferlies’ which old writers used to place in _terræ incognitæ_, and have their analogues in the writings of Herodotus and Aelian, and, Mr. Stokes says, Megasthenes, to whom we may add Lucian and Sinbad. The majority of them, however, are variants, and often developments, of topics common in Irish legend. We must content ourselves with giving a brief summary of those episodes which most illustrate the development of the Otherworld legend in Irish ecclesiastical literature. As usual, the narrative mainly consists of the visits paid by the wanderer to a number of enchanted islands, which are mostly of the usual Wonderland pattern, though the present description of them contains, in most cases, certain distinctive features of its own. The wanderers are entertained in stately dúns, with walls and palisades of the precious metals or of crystal; they are regaled with magic food; there is the usual Calypso episode, etc. etc. One island is raised above the sea upon a pedestal; in another is a river of fire; one is encompassed with a wall of water; over another a stream rises on one side and descends on the other, forming an arch like a rainbow; upon another is a tall column with a mystical veil depending from it and enshrouding the island,--all of which recall features of the Paradise described in the _Fis Adamnáin_.