“The United Nations Educational, Scientific and Cultural Organization (UNESCO) seeks to encourage the identification, protection and preservation of cultural and natural heritage around the world considered to be of outstanding value to humanity.” (quoted from the UNESCO website)
The UNESCO list of World Heritage Sites plays a central role in these efforts. While on the one hand many states and places aim for inclusion on the World Heritage Site list as it can help boost tourism, the official approval also comes with the cost and effort to preserving and protecting the site adequately which can be a costly and complicated issue.
Not least these considerable efforts are one of the reasons why there is a particular imbalance in the distribution of 832 cultural heritage sites that existed in 2017. These are more likely to be situated in wealthier nations, although countries such as the USA are also less present here for political reasons.