What should visitors to Athens see? After the treasures of the Acropolis, the National Archaeological Museum and the New Acropolis Museum, which is slowly acquiring its own marbles while awaiting the return of the rest from exile, the Goulandris Natural History Museum is a must. With its new acquisition, the Gaia Center for environmental research and education, the museum has long been in the vanguard of the campaign to save the planet. Niki Angelou Goulandris, co-founder and president of the museum, former deputy minister, Woman of Europe in 1991, and creator of Gaia, was devoted to protecting nature long before it became fashionable. May 18, tomorrow, is International Museum Day and a perfect opportunity to visit the Goulandris Natural History Museum and the Gaia Center, which will be open from the morning till midnight, free of charge. The garden of the museum is the only large green space in the center of Kifissia, and, with its vast range of plants, trees and aromatic and pharmaceutical herbs, is a fine opportunity for children to get to know living plants. All the staff will be there, together with volunteers, to show visitors around. In the atrium there will be screenings of two excellent documentaries made by the Nicolas Hulot Foundation in cooperation with UNESCO and the French Foreign Ministry, as well as the French Ministry for the Economy and Sustainable Development and sub-ministry for research. On the occasion of International Museum Day, the exhibition «Climate Change and Human Intervention» will open ahead of the official opening in June. The museum is holding the exhibition jointly with Villette, Cite des Sciences, Paris.