Foundations, in both senses of the word, naturally play an important role in architecture. Histories and theories of architecture rely upon ideas of foundations and beginnings. On the occasion of its fiftieth anniversary, the ETH Zurich's Institute for the History and Theory of Architecture (gta) set out to address the problem of beginnings, looking at its own history and that of architecture in general while analyzing the role of founding myths in particular. As architecture's continual recourse to concepts such as the primitive hut or the three Vitruvian principles (firmness, utility and beauty) show, myths occupy an important place in professional discourse. The contributions to this issue of gta papers question the tradition of these myths, their potential for interpreting the past, and their role in the design of future projects.