A skyscraper one mile high, a dome covering most of downtown Manhattan, a triumphal arch in the form of an elephant: some of the most exciting buildings in the history of architecture never got built. As Philip Wilkinson relates here, it was not usually poor design that stymied them; politics, inadequate funding, or a client who chose a "safe" option were all things that could stop a project leaving the drawing board. In this illustrated look at the seemingly impossible, Wilkinson shows how these nonstarters have nonetheless paved the way for ambitious structures that were eventually built, like the Eden Project and the Shard.