Properties with a relationship to science are amongst the least represented on the UNESCO World Heritage List and the values of these properties, located in all the regions of the world, are not sufficiently recognised. The UNESCO and IAU encourage the States Parties to the World Heritage Convention to actively participate in the development and implementation of the Thematic Initiative “Astronomy and World Heritage” aiming to provide an opportunity to identify the properties connected with astronomy and for keeping their memory alive and preserving them from progressive deterioration, through the inscription of the most representative properties on the World Heritage List.