The red triangle. One of the oldest industrial enterprises of the city of St. Petersburg.The first rubber factory in Russia.Since the beginning of the 2000s, the factory buildings have been in a deplorable state. Most of the plant's premises are abandoned. The windows are broken. And the territory of the plant itself no longer belongs to its original owners and is attractive for lovers of the aesthetics of abandoned buildings. Several shoe companies operate in separate buildings of the industrial zone, but the volume of production of rubber shoes is very small.Sevkabel Port is a favorite place for residents of St. Petersburg in the Harbor of Vasilievsky Island. A recently closed industrial area, today it is one of the most welcoming and hospitable spaces of the city. All the monuments of industrial architecture that are on the territory are carefully restored, endowed with new modern functions. And the architectural concept of the project delicately emphasizes the historical memory of the place. There are various functional zones on the territory of the Port where you can create projects, work, spend free time, engage in creativity and sports. There are bureaus, workshops and offices, exhibition, concert and sports halls, children's studios, shops and showrooms, restaurants, cafes and bars.Today, the share of the so-called "gray belt" in the central part of the city is almost 40%. The appearance of the "gray belt" is a feature of more than one St. Petersburg. Many cities in Europe, and indeed all over the world, have faced this problem to varying degrees. Based on convincing examples of renovation of depressive zones, we are able to adapt former industrial buildings to new functions!