A settlement may be defined simply as a group of buildings with people living in them. Settlements rarely emerge gratuitously but are rather the result of factors rooted in functionality.

Fertile alluvial plains where a secure water supply is available, e.g. Ganges Valley in India, have basic requisites of human existence and are the most densely populated areas of the world. A flat plain that facilitates movement of people and exchange of goods and ideas can become an important centre of communication, trade and administration. Paris, in the intensely cultivated Paris Basin drained by the River Seine, is a good example.

Another well-prized region for the emergence of settlements is the coastal lowlands, with calm waters and sheltered lagoons. These locations are also well suited for harbour development. Port Louis and Singapore owe their growth to these factors where wharves and dockyards have been built in the sheltered curved bay.

People also choose to settle where there is a natural focus of routes. These nodal settlements help people to congregate and provide commercial and social services to themselves and to passing travellers. Chicago owes its growth to its nodal location in the mid-west of the United States, with roads and railways converging towards it from East, West and South.

Industrial cities have developed where waterfalls exist. These are natural sites for generating electricity. Buffalo is an example of a large city at the top of the Niagara Falls whose growth is associated with the development of cheap water power.

Lakeside settlements are also famous as lakes provide fish, water and a means of inland transport. Some of the best tourist centres are located near lakes because of their scenic beauty and recreational facilities. Como, located close to Lake Como in Italy is one of the most hectic tourist resorts in Europe.

Many settlements have grown due to the presence of mineral wealth, too. Eldorado is a term that speaks for itself. Johannesburg grew as a city with the discovery of gold to become the second largest city in South Africa today.

Some old settlements like Beijing and Edinburgh grew on sites which were ideal for defence. While the first is well fortified by the Great Wall of China, the strategic capital of Scotland was once a fortress, standing on a rocky crag.

The presence of water has always attracted settlements and river-side sites are numerous. Orleans on the River Loire takes advantage of the inside bend of the river. Towns develop at the confluence of rivers where river navigability is maximal, like Khartoom, at the confluence of the Blue and White Nile or St. Louis where the Mississippi meets the Missouri.

The global world in which we live has its own rationale. Today, human beings need not meet in person to exchange goods, services and ideas. Consequently, virtual settlements are emerging along Internet highways, without using a single inch of natural site. Thus, the postal address is being replaced by the e-mail address.