To the modern mind, the search for El Dorado, Amazonia’s fabled city of gold, has come to symbolise the ultimate fool’s errand, even more than dredging Loch Ness for a cryptozoological monster or looking for Elvis in far-flung locations. El Dorado is the quintessential fantasy.

Andrew Lees grew up blissfully besotted nonetheless. As a bookish child in postwar Merseyside, the idea of a gilded metropolis hidden deep in the Brazilian rainforest gripped his imagination. Responsibility for this boyhood fascination fell to a certain Lieutenant Colonel Percy Fawcett. During one of their regular library visits, Lees’s father unearthed a copy of Exploration Fawcett and handed it to his son. ‘You’ll enjoy this,’ he told him. ‘It’s about an explorer who vanished without a trace in the Amazon.’