The aim of this study is to present a novel measure of which pairs of human-made factors are most threatening to a Cultural World Heritage Site when time as well as its characteristics, including location, are controlled for. A system of Probit equations is employed on information from the UNESCO State of Conservation and World Heritage databases on the nine most frequently reported external threats (housing, tourism, transportation, destruction, illegal activities, land conversion, accommodation supply, loss of identity and war and civil unrest). This allows an analysis that covers all sites, with 22,190 observations over a time period of 45 years. Threats from war and civil unrest, destruction of heritage and illegal activities all appear in pairs and are strongly correlated with each other. There are also high positive correlations between threats from housing and land conversion, tourism and housing, accommodation and transportation as well as tourism and accommodation. Until 2009, there is an increase in the probability of threats, after that, stagnation is observed. Cultural World Heritage Sites in Africa and the Arab countries face the highest risk of a reported threat. Based on the novel measure, a second step of the analysis employing fixed-effects Logit estimations reveals that threats from tourism, housing and transportation are more seldom identified if the site in question has a management plan.