World Heritage Sites are selected based on their outstanding universal value and their significance to humanity. The selection process is overseen by the United Nations Educational, Scientific and Cultural Organization (UNESCO).

The process for becoming a World Heritage Site typically involves the following steps:

1. Submitting a nomination: A country must first identify a site within its territory that it believes meets the criteria for selection as a World Heritage Site. The country must then submit a nomination to UNESCO, including a detailed description of the site and its significance.
2. Evaluation by UNESCO: UNESCO evaluates the nomination and determines whether the site meets the criteria for selection as a World Heritage Site. This evaluation is carried out by the World Heritage Committee, which is made up of representatives from different countries.
3. Decision by the World Heritage Committee: The World Heritage Committee makes the final decision on whether to inscribe the site on the World Heritage List. If the site is selected, it will be added to the list and will receive protection and support from UNESCO.

The criteria for selection as a World Heritage Site are divided into cultural and natural categories. To be considered for selection, a site must meet one or more of the following criteria:

Cultural criteria:

• Represent a masterpiece of human creative genius.
• Exhibit an important interchange of human values, over a span of time or within a cultural area of the world, on developments in architecture or technology, monumental arts, town-planning or landscape design.
• Bear a unique or at least exceptional testimony to a cultural tradition or to a civilization which is living or which has disappeared.
• Be an outstanding example of a type of building, architectural or technological ensemble or landscape which illustrates (a) significant stage(s) in human history.
• Be an outstanding example of a traditional human settlement, land-use, or sea-use which is representative of a culture (or cultures), or human interaction with the environment especially when it has become vulnerable under the impact of irreversible change.
• Be directly or tangibly associated with events or living traditions, with ideas, or with beliefs, with artistic and literary works of outstanding universal significance.

Natural criteria:

• Contain superlative natural phenomena or areas of exceptional natural beauty and aesthetic importance.
• Be outstanding examples representing major stages of Earth’s history, including the record of life, significant on-going geological processes in the development of landforms, or significant geomorphic or physiographic features.
• Be outstanding examples representing significant ongoing ecological and biological processes in the evolution and development of terrestrial, freshwater, coastal, and marine ecosystems and communities of plants and animals.
• Contain the most important and significant natural habitats for in-situ conservation of biological diversity, including those containing threatened species of outstanding universal value from the point of view of science or conservation.

Overall, becoming a World Heritage Site is a prestigious and highly selective process that recognizes the cultural and natural significance of a site and aims to preserve it for future generations.