Machu Picchu – Stonework
The central buildings of Machu Picchu use the classical Inca architectural style of polished dry-stone walls of regular shape. The Incas were masters of this technique, called ashlar, in which blocks of stone are cut to fit together tightly without mortar. Many junctions in the central city are so perfect that it is said not even a blade of grass fits between the stones.
Photos by Ravi 
Machu Picchu is so high on my travel wish-list!!
It will be worth it, Janaline
Interesting info, wonderful photo, Ravi.
Thanks Donna!
What masters of stone they were!
They sure were, Pat