Globus Cassus is an art project and book by Swiss architect and artist Christian Waldvogel presenting a conceptual transformation of Planet Earth into a much bigger, hollow, artificial world with an ecosphere on its inner surface. It was the Swiss contribution to the 2004 Venice Architecture Biennale and was awarded the Gold Medal in the category "Most beautiful books of the World" at the Leipzig Book Fair in 2005. It consists of a meticulous description of the transformation process, a narrative of its construction, and suggestions on the organizational workings on Globus Cassus.