Welsh is the traditional language of all Britain (south of the Highlands) before the coming of the "German" Saxons. It is also the language of King Arthur, Merlin and many other tales. This lends Welsh a quite mystic and emotional feel, further enhanced by being spoken in the mountain regions of Welsh. Thus, Welsh is a very ancient cultural language. However, it is also a very healthy modern language, being used in all spheres of modern life in Wales.
I first started to learn Welsh using some other books, but as soon as I began with this book I realised that it was superior to the others. True, the first two or three chapters could be a bit more organised, but apart from that the book has got it all. The grammar is very well explained and the learner really gets to know every aspect of the grammar of spoken Welsh. All lessons have got some dialouges with extensive word-lists and a lot of excersises. As the icing on the cake, you also get an introduction to different aspects of Wales and Welsh in every chapter, with short introductions about dialects, eisteddfodau, Welsh politics etc.
I have visited Welsh a number of times, and I have found that this book has helped me a lot. I have been able to communicate extensively with Welsh speakers, I have taken part in cultural activities in Welsh, I have been able to read the Welsh epics.
Of course, to really learn a language you have to speak it with its native speakers, but this book is the best tutor you could get and I do not doubt the Finnish reader below who says that he went to Wales and communicated in Welsh after completing this excellent course.