New undercrossing for the bridgehead square in front of the Kantemirovsky bridge (through Neva River) in Saint-Petersburg, Russia.Our team aimed to preserve the unique urban scenery, which includes the precious old 19-century factory and good soviet glass/metal/concrete modernist office buildings. The streetview cityscape remains clear, as we buid uder the ground.The visual opposition of the ground pavilions to the brick-style factory (heritage) leads us here to the use of combination of brick walls and u-glass walls. The brick walls include the parametric see-through brickwork. We combine the staircases with elevators to let all categories of the citizens fell free to use this new infrastructure.