concrete jungle 
noun
A city or urban area which has a high density of large, unattractive, modern buildings and is perceived as an unpleasant living environment: a three-room flat in the concrete jungle of suburban Moscow...
- He is more like a spiderman in the modern concrete jungle of the city.
- It goes without saying that development is often at the cost of the environment, replacing green spaces in big cities with concrete jungles.
- ‘But as we can see now, the whole area has turned into a concrete jungle where residential areas are confronted with shopping malls,’ he told the Post.