Discovering Llactapata - the movie
the original documentary film by Hugh Thomson of the 2003
Thomson - Ziegler RGS expedition that re-discovered Llactapata
The Story of Llactapata: Machu Picchu's Observatory
The discovery of the Inca Sun Temple near Machu Picchu
Machu Picchu; Stable as a Rock
An overview of the geology of Machu Picchu