In the article Semiology and Urbanism (1967) Roland Barthes points out that it is important to bring an approach to the city which goes further than a metaphorical level. He points to a real level. The metaphor treats the city as a picture but not necessarily the real city. But he gives no further details about this real level (although he mentions Freud’s dream theory).
At the moment the Danish State is working in the streets and squares of Copenhagen. They are constructing a wholly new metro system. Until now transport in Copenhagen has unfolded overground; on bikes, in cars and busses. With the use of heavy machinery, the excavation works are in a very concrete way penetrating beneath the picturesque surface of the city. Usually you never see large deposits of mud and clay in a city. They are digging 5 or 6 giant holes in key locations as preparation for the concreting of new stations. The holes are as deep as the buildings which surrounds them are high – sometimes deeper. Cities usually strive for the sky; and the direct opposition to this movement makes these holes disturbing. They reintroduce in the city a somehow repressed but dynamic world; a world which our ancestors probably fled from when they began to live in large settlements, and then cities, in the first place. A world with its own timescale and its own imperceptible flow.
It took only a few months to dig through the layers of culture: first a layer with still functional infrastructure; cables, pipes and sewers, then a historic layer; a section of Copenhagen’s old fortifications was found and excavated and then a layer of fill placed there by man over the last 1000 years to reclaim the land from the sea. Now the excavators face a reality of mud and clay. In the first 10 metres under sea level the machines are working through deposits from the ice ages. Layers of mud, boulder clay and moraine sand. The ice from the last ice age melted 15.000 years ago. At that time most of the Copenhagen region was covered by marsh and swamp. Over a period of a few thousand years, plant and animal life slowly invaded the dry territories with the concomitant milder climate. During the present period, the quaternary period, which includes the last 2-3 million years, the region has been covered by ice four times. The glaciers that moved over the region carried clay, sand and mud from the north. Materials made from disintegrated bedrock due to the friction from the ice and other processes of erosion. The ice moved only a few metres every year and slowly raked up and changed the landscape and coastline. The last ice age lasted 10.000 years and the ice sheet, sometimes up to two kilometres thick, slid heavily over the Copenhagen region. The ice left the mud, the clay and the sand for the excavation workers mixed without any clear layering.