The proposal for the extension aims to achieve a unique and remarkable experience in Joenniemi, location of the existing Museum. Reacting to a pleasant architectural and landscape environment, where the natural structure has a great impact in the whole system of Mänttä. The extension implementation brings to the site new ways of dealing and discovering this extraordinary area. The sensitive insertion of the extension purposes a long volume towards to the lake direction and partially attached to the existing building west façade, which configures the entrance and the new foyer, either for the existing building and extension. The positioning of the extension redefines the park area and orientates to the most important views, creating a strong scenographic atmosphere. The landscape values identified in the site, led the extension proposal to be explored by the visitor in different moments, either in interior or exterior (public) spaces, trough various routes linked by platforms and ramps, offering a close relation between exhibitions route and the natural surroundings. The inclined roof is accessible from the entrance side, generating a platform which culminates in a podium where the visitor can achieve a panoramic view towards the lake and the surrounding landscape.