During his time spent in the U.S., Gianni Pettena nourished his research on space by drawing on the proposals then being made in Land Art. With his Ice House I project, he took advantage of the icy winters of Minnesota and poured water over former administrative offices. The building froze overnight, becoming entirely covered with a translucent layer of ice. Only perceptible through this new skin of ice, the architecture as such became invisible. Rendered mute and inoperative, making all use or habitation impossible, architecture is transformed into a critical experiment. In Ice House II, Pettena built a superstructure in wood over which he then poured water, thereby imprisoning a suburban house in a cube of ice. Ironically, the architecture here suddenly recalls another origin, the one of Platonic solids and their formal ideality, prior to the ice cube gradually melting away. Through this passing from a liquid state to a solid one, Pettena’s ephemeral monoliths are designed to imbue architecture with the immanence and the temporality of nature. The architecture and the landscape meld into a single reflection. The addition of the ice paradoxically leads both to the disappearance of the “architecture” as object and to the crystallization of present time into an image of eternity.