Concrete jungle and Conurbation

Concrete jungle noun - An area in a city with large modern buildings that is perceived as dangerous and unpleasant.

Conurbation and concrete jungle are semantically related. In some cases you can use "Conurbation" instead a noun phrase "Concrete jungle".

Conurbation noun - An aggregation or continuous network of urban communities.

Concrete jungle and conurbation are semantically related. You can use "Concrete jungle" instead a noun "Conurbation".