MARS Architects snagged first place in an international competition to design the headquarters and activity center for Walltopia, a leading global producer of artificial climbing walls and grips. Located in Sofia, the Collider Activity Center will mark the city's first green mixed use center to combine both leisure and exercise space. To tie together the site’s diverse programs, the architects inserted a series of dramatic climbing atriums into the folds of the building, creating a continuous climbing experience.
To achieve a compact spatial system, MARS Architects cleverly folded the activity center into a zigzag shape and added bright yellow climbing atriums into each void to create a canyon-like “spatial backbone.” As the building slopes upwards, each climbing section advances in difficulty and height, from the beginner’s area to the pro section. The large climbing voids also allow for natural light to permeate deep down into the building; one of the atriums will double as a greenhouse in the summer.
The activity center was also dramatically slanted to minimize the heat load and to avoid casting shadows over the neighboring park and event stage. A rooftop bar is located at the highest point of the building to take advantages of views overlooking Mount Vitosha, one of Bulgaria’s most popular tourist destinations.
In addition to climbing and boulder areas, the Collider Activity Center will incorporate additional exercise and leisure space including a multipurpose sports room, swimming pools, spa, offices, bar and restaurant. Placed along a major axis in Sofia, the multi use building will serve as a major city landmark as well as a buffer between the urban fabric and surrounding landscape.