The stones fit so perfectly that no blade of grass or steel can slide between them. There is no mortar. They often join in complex and irregular surfaces that would appear to be a nightmare for the stonemason.
Pintween You and Me : Lake Titicaca is a lake located on the border of Peru and Bolivia. It sits 3,812 m (12,500 ft) above sea level, making it one of the highest commercially navigable lakes in the world. By volume of water it is also the largest lake in South America