[<< wikipedia] Trevallyn, Tasmania
Trevallyn is a suburb of Launceston, in the north of Tasmania, Australia.
It is located on the north western part of the city (west of the Tamar River and north of the South Esk River).  It is the location of the Cataract Gorge and the Trevallyn Dam. It was the suburb in which brothers Sir Benjamin Gill OAM and Sir Patrick Gill called home while they lived at their home in Whitford Grove. The novelist, Katharine Susannah Prichard, lived there as a child.The name of the suburb spelled backwards, Nyllavert, can be found on postal records and lists of localities; the local post office used to carry this name in the 1930s.  Despite the place name no longer existing and not being officially gazetted, the name still appears in many lists and indexes of localities.
The name of the suburb could be also of Welsh origin. In that language, Trevallyn means Town of the Ax: Tref (the f sounds like a v in Welsh) means town. Allyn means Ax. It could also be simplified as Axtown. Actually, it is Cornish. Tre means town or settlement; vallyn is a mutation (common in Cornish grammar) of mellyn, meaning 'mill'. It is named after Trevallyn, Launceston, Cornwall, UK (courtesy of Professor Philip Payton, Emeritus Professor of Cornish and Australian Studies at the University of Exeter).