I have been spending prolonger periods of time in Lisbon, and thought I felt a 'local' there. I thought I knew all of it - its unique Old City and other sights to see, the places to hang out, things to do. I would have never thought that I would need a guidebook. In fact, Lisbon is a very easy and relatively inexpensive city to get around (unlike chaotic Rome, ... London, or confusing Asian cities). It is a wonderful place, which I thought I could fully enjoyn without the help of any guidebook. Yet, even for someone like me who knows the place and speaks the language, this Lonely Planet guidebook proved extremely useful. It is indeed one of the best LP books I have ever used - extremely well-written, entertaiting, easy-to-use, and filled with precious information. I thought I had seen all the beautiful sites, but this guidebook led me to even more places which I would have not otherwise found: to beautiful coast resorts just outside the city, Estoril just on her outskirts, etc. - with full advice on places to visit, to eat, etc. I thought that I knew what to do at night (it's not hard to find night life in Libson), but this guidebook opened my eyes even more to the wonderful life of the city after dark: the less-known discos and cafés with live music from São Tomé e Principe or Cabo Verde, the Angolan and Mozambican restaurants, etc. Also, I had been unable to find more 'formal' places for business lunches, and this book has that also ! All this is, without mentioning the excellent coverage on the city's history, art, architecture - an excellent guide indeed to her museums, churches and other sites. So, even if you do feel confident, don't go to Lisbon without it - you might be missing something you would not otherwise find.