Cluj-Napoca is a city of young people with 25% of its population studying in universities. Student life means also sports and the tradition is consistent. The new Multifunctional Sports Hall is the newest piece of public infrastructure for training, championships and cultural events, in a building conceived to be part of an ensemble together with Cluj Arena, the soccer and athletics stadium also designed by Dico and Tiganas and opened in 2011. Both objectives have generated new public spaces relating the Central Garden of the City with the river Somes banks promenades, towards a Sports park and another public garden in a sequence of public spaces of almost 2 kilometers. The envelope of the building is a simple box including another box which contains the main hall, of 7.227 seats and up to 10.000 people for concerts. The facade is an assemblage of layers reflecting and transmitting the light into the foyers inside. The outer mask is mesh of parametrically distorted rectangles inspired by the nets used in several ball sports. The perforated steel plates are forming 3D pyramids reflecting the sky and the sun at every time in different angles and colored effects. The building has a permanent dialogue with the people from the street through the challenge to read the geometry of the facades, being the same time introverted. Inside the public will be guided by 4 thematic colors corresponding with the cardinals. The main hall is a stage and a backstage in the same time, bringing together the public and the performers in a black box with all equipments apparent but camouflaged. From shinning white with golden accents to dark grey and black ambiance, from outside to inside and backwards, architecture is built by light and colors.