Vincent Callebaut Architects are known for their visionary floating green projects. But the Lilypad Floating Ecopolis is an exceptional example. Designed for “ecological refugees” in the year 2100, the Lilypad is an amphibious, self-sufficient city. The design can accommodate 50,000 people along with the plants and animals they need to survive. The lower portion of the craft features a submerged lagoon which purifies rainwater to provide fresh water for the inhabitants of the Lilypad. Whether designs like this ever come to pass depend largely on the Earth’s future climate, but even as a concept the Lilypad is captivating.