National Geographic : 1913 Apr
Photo by Hiram Bingham THE MOST INGENIOUS LOCK IN MACHU PICCHU The gateway to Ingenuity Group had lock-holes differing from those of other groups (see pp. 464, 466-467), in that they were cut out of single blocks of stone and had the stone cylinder not set into, but forming part of the whole block (see also page 471). Photo by Hiram Bingham A TYPICAL HOUSE DOOR: MACHU PICCHU The doors of the houses were carefully made and are all narrower at the top than at the bottom. The lintels are usually made of two blocks of stone. The Indian boy in the picture is carrying the kodaks and a large map, in ten sheets, on which are shown all the houses.