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THE NATIONAL GEOGRAPHIC MAGAZINE 



"" Arrial T^x-plorntions. Inc. 

 THE GREAT WALL OF PI'RU. t.TKE TTTA'I" OF CTIINA, MA\ IIANI- 

 UiaM'XEi:!) KW'ASION 



Across the Santa River delta and up into tlie liills it twists, crossing dry river beds, climbing 

 sharp ridges, and swooping into valleys. The author and his companions followed it for 40 miles 

 by airplane, yet, they believe, explored only a small portion of its length. Almost certainlv it was 

 erected to stem the tide of Inca warriors who once harried the country. At intervals along its 

 sides are sturdy forts. 



