Major Inca sites are still being discovered in this jungle region. In April 2002 British explorer Hugh Thomson – author of The White Rock – and American archeologist Gary Ziegler, following rumours of a lost city, led an expedition, which discovered an Inca city in the virtually inaccessible valley bottom at the confluence of the ríos Yanama and Blanco in the Vilcabamba region. Apparently seen briefly by Hiram Bingham nearly a hundred years ago, the coordinates were never recorded and this settlement of forty main buildings set around a central plaza hadn’t been spotted since. Although very difficult to access – due to river erosion – there appears to have been an Inca road running through the valley, probably connecting this site to the great Inca citadel of Choquequirao. This settlement is believed to have been Manco Inca’s hideout during his rebellion against the conquistadors, which lasted until his execution in Cusco in 1572.