This water theatre by the British architect, Sir Nicholas Grimshaw of Grimshaw Architects, takes the form of a vertical seawater greenhouse, with the evaporators and condensers stacked vertically to maximise yield. The structure is not only a visible engine of sustainability but is also a large theatre auditorium. The proposed project is located in the post-industrial port area of Las Palmas in Spain’s Canary Islands and takes advantage of its two unique geographic features – steep beaches, so that cold water is close at hand, and a steady wind direction. Grimshaw worked with and based the project on an idea by Seawater Greenhouse, who are experts in converting sea water to fresh water. The project highlights where architects do their best work – when they are part of a team with enough specialist knowledge to achieve a broad goal.