Pamukkale forms an important backdrop to the original Greco-Roman town of Hierapolis and the cultural landscape which dominates the area. Criterion (iii): Hierapolis is an exceptional example of a Greco-Roman thermal installation established on an extraordinary natural site. Visitor access to the travertine terraces is prohibited in order to sustain the water flow and to maintain the colour and structure of the travertine terraces. An advisory board, composed of central and local administrations, non-governmental organizations and scientific groups (in particular the head of the excavation team) provides recommendations to the Site Management Directorate concerning projects in the site. This includes accessibility and visitor management, policies for enhancing perception of the site, and risk management.