In the early nineteenth century, stories emerged of mysterious ruins that lay buried and forgotten, deep inside the jungles of Central America. But a lost civilisation in this region was thought to be impossible in the 1800s. Everyone knew that the continent had only ever been peopled by savages, and they couldn't have created such sophisticated structures. But then a young American lawyer named John Lloyd Stephens, and a British artist, Frederick Catherwood, went to seek out these ruins for themselves. They travelled hundreds of miles through the jungles of Mexico, Guatemala, and Honduras and eventually uncovered forty-four buried and forgotten cities. All with a common architectural style that confirmed that there was once a single, vast civilisation that had existed in a place where nobody believed there could be one. But, for all their extraordinary revelations, there was still one question they could not answer. Who were the people who built this place?