ECHOPOLIS International 2018 entitled "Nature and Culture-based strategies and solutions for cities and territories : an idea whose time has come !" is an occasion to reflect on the place that cultural and natural heritage occupies both in our lives and in territorial and economic development and to alert about the need to protect such unique values for the future generations. Nature and culture are considered as an indivisible whole. Natural and cultural heritage should be recognized, understood, planned and managed together!