What kinds of natural features would likely exist in a densely populated area of the world

Natural features of a densely populated region:

There are some regions around the globe where the over all number of individuals living inside a the regions is very high, as the region is mostly commonly referred to as the Urban area or a city. It is due to the fact that as advancement were made in the industries and more companies and plantations were done for better productivity the people working in these industry started living near them. Obviously if a worker lives near his company or industry it will benefit both the firm and the worker.

Explanation:

Less space for trees and water resources inside the Urban area:

A high density of population needs to be adjusted in the area by construction of various buildings or we can say places to live. As these constructional areas will spread out in most of the region, some how making less space for trees and other natural resources to grow.

Noise and Air pollution:

We will have a large number of machinery which is operational inside many industries and then there is traffic. As these factors are much likely to increase the rate of both noise and air pollution. Along with that waste material which is untreated properly by the management, will cause water and air pollution. As industries will generate smoke by running large machinery and due to high density of waste products releasing in the clean environment leading to damaging the environmental resources.

U mean cites? in the phrase of densely populated area?