asphalt jungle

plural asphalt jungles

1. idiomaticA city or urban area, where the landscape is covered by pavement and the environment is alienating and unsafe.

   The sound track tingles with cool jazz, the dry atonal music of the asphalt jungle.

   1962 July 27, “Manhattan's Lower Depths”, in Time (film review of Strangers in the City), archived from the original on 07 Mar 2012

   1 more example

   Harlem comes through as an urban hothouse mean with exotic hustle and violence, a tangible asphalt jungle with its own abrasive laws of motion.

   1976, A. Robert Lee, “Violence Real and Imagined: The World of Chester Himes' Novels”, in Negro American Literature Forum, volume 10, number 1, page 13