The Wadden Sea UNESCO World Heritage site is the largest unbroken system of intertidal sand and mud flats in the world. It encompasses almost the entire Wadden Sea in Denmark, Germany and the Netherlands.

Around the world 1154 sites are on the UNESCO world heritage list (November 23, 2021). They achieve their status based on cultural and/or natural values perceived to be of Outstanding Universal Values (OUV). The goal is to preserve these sites for the future.

On the 25th of September 2015, the UN General Assembly adopted the UN Sustainable Development Goals. With 17 goals and 169 targets, the world leaders created a fundament to work towards a sustainable future.