The Westman Islands’ national festival is unquestionably the best known festival attracting the greatest number of mainland visitors. Held in Herjólfsdalur on the first weekend in August, it is a 3-4 day outdoor festival where having a good time is everyone´s easily fulfilled aim. The whole weekend is packed with entertainment of all description, including the traditional bonfire, fireworks and the famous “hillside sing-along”. Specially built structures fill the valley, not to mention the large white tents of the locals who literally move house during the festival and prove their famed hospitality by welcoming guests for coffee,smoked puffin and sundry other delicacies.
Information got from http://www.vestmannaeyjar.is/
see more information about the festival here
picture from http://svanurg.blog.is