Cutting Edgegianluca milesi architectureGianluca Milesi, Stefano ElayathambyWalltopia, Collider Activity centerInternational Competition, Sofia 2013We thought this project as an opportunity to create a vision and a landmark for Walltopia and the city of Sofia.Through a contemporary imntellectual attitude and a precise architectural language we propose a poetic approach to the theme of sport activities and free time.According to the competition program we choose anartistic and sculptural-scenic solution that can give quality to the area, the park and the city.Reading the requests of the program and in relation with our idea we decided for the design of a single building volume containing all the function for the convenience of the organization of the functions themselves and also for economical reasons.The building we propose is placed on the side on the east-west direction in order to be at the same time a filter and a connection between the city and the green area to be expected in the north side of the lot.Furthermore the shape and the orientation of the main volume is articulated according to two directions in considerations of the alignments of the property lot and in a way to use all the panoramic potentials of the area.The formal idea/concept is directly related to the image of the mountains and the rocks and their cracks and cuts. In order to reach this result whit thought to a Corten perforated plate skin wrapping the whole building designing neat but not regular lines.The Corten perforated plate allows the passage of the light and the view to the exterior in every part of the building. Beside this, the skin is cracked by vertical and oblique cuts in particular points in order to have a perfect visual communication. The skin wraps the core building that is a glass structure sustained by steel pillars and trusses.Regarding the organization of the function of the building we thought convenient to locate on the ground floor the activities that were able to established a connections between the plaza facing the city and the green area behind. For this reason we placed on the ground floor a double height entrance and distributionhall hosting the main vertical connections, the coffee shop, the climbing hall, that is developing itself till the top of the building and finally the restaurant, directly connected to the green area and the summing pool.The coffee shop, organized on two floors, is intended as a fulcrum between different function such as the climbing hall and fantopia and is easily reachable from the spa and the fitness space located on the first floor.On the second floor are located the multifunctional hall and part of the required office spaces that occupy the entire fourth floor. The mechanical rooms are located underground.The last floor of the building hosts the roof coffee shop from where is possible to access to a panoramic view terrace and at the same time to have a good view to the climbing hall from above. This visual communication is in any way maintained at all floors of the building.In the climbing hall are provided climbing walls and boulders according to the number and the needs of the climbers and this space is particularly open to the exterior through the cuts on the skin and though a big opening facing the plaza. The park-green area is organized on a linear scheme perpendicular to the main facades of the building. Several boulders and even climbing walls are scattered in the park, the swimming poolsare directly connected to the restaurant while the event stage area is in the north side.The green house, designed using the same languageof the main building, a glass box wrapped by a Corten perforated plate, is located on the west side of the park, visually connected to the main building. All around the green area is articulated a cycling path.The parking area is on the extreme north, far away and secluded from the park and the main building.Our poetic way to work and design wants to satisfy all the needs of a well working Activity Center conjugating at the same time architecture, aesthetic, physical needs, open air life style and leisure.