Every night, astronomers use a new generation of giant telescopes at observatories around the world to study phenomena at the forefront of science. By focusing on the history of the Gemini Observatory - twin eight-metre telescopes located on mountain peaks in Hawaii and Chile - Giant Telescopes tells the story behind the planning and construction of modern scientific tools, offering a detailed view of the technological and political transformation of astronomy in the post-war era. McCray describes the ambitions and machinations of prominent astronomers, engineers, funding patrons and politicians in their effort to construct a modern facility for cutting-edge science - and to establish a model for international co-operation in the era of megascience. Besides exploring how and why scientists embraced the promise and potential of new technologies, McCray considers how these new tools affected what it means to be an astronomer.