The contemporary world struggles with environmental crises and cultural breakups, as well as urbanization polemics; therefore, a rethinking of the design of urban landscapes emerges as a philosophical, ethical, and practical necessity. Traditional landscape design approaches, which are largely based on the control and domination of nature, are not capable of solving these transformations. This research analyzes the role of key concepts by Gilles Clément, such as the "Garden in Motion ", the "Planetary Garden" and the "Third Landscape", in the direction toward sustainable urban landscape design. The present study employs qualitative research methods together with epistemological, interpretive, and semiotic approaches. Data was acquired using content analysis of Gilles Clément's works and paintings, historical reviews of the development of landscape in France, and analyses of implemented projects, such as Parc André Citroën, Musée du Quai Branly Garden, Saint-Nazaire Submarine Base and Derborence Island. The results show that, in Clément’s view, the landscape is considered a living and dynamic process that emphasizes human-nature cohabitation, ecological dynamism, and the regenerative creativity of abandoned places. The appreciation of these concepts could offer a theoretical and practical foundation for sustainable design of urban landscapes while simultaneously addressing functional requirements as well as cultural, aesthetic, and ethical values. The epistemology of Clément's concepts can serve as an inspiring model for urban landscape design in the face of contemporary environmental crises a model that, by revitalizing abandoned lands, strengthening green infrastructure and enhancing ecological awareness and responsibility, opens new horizons for sustainable urban planning.