Thomas Sieverts (born 1934) is a German architect and urban planner. He is the author of Zwischenstadt (1997; first published in English in 2000 as Cities without Cities: An interpretation of the Zwischenstadt), a book which addresses the decentralization of the compact historical European city and examines the new form of urbanity which has spread across the world describable as the urbanised landscape or the landscaped city. Sieverts calls this the Zwischenstadt, or "in-between city", as it exists between old historical city centres and open countrysides, between place as a living space and the non-places of movement, between small local economic cycles and the dependency on the world market. In 2008 a group calling itself "suddenly" commissioned the American writer Diana George to make a new translation of Zwischenstadt which they published as Where We Live Now (the English phrase George chose as the translation of Sieverts's neologism "Zwischenstadt"). In October 2008, Sieverts came to Portland, Oregon, on the occasion of the book's publication to take part in a week-long symposium about his work, also called suddenly.