There's a British TV documentary on Youtube I watched last week where a professor of sculpture and another amiable British academic tried to emulate the Olmecs of Mesoamerica. They could neither carve an eyebrow in a large stone or move it a few yards to its destination using the 'tools of the day' and gave up hope, comprehensively humiliated and unable to offer an explanation.
I didn't post it as I'm more interested in the Olmecs themselves than stuffy British academia failing miserably to do what was done in ancient times but this video is non stop perfectly aligned beautiful rock and I could look at it all day. It makes me want to fly to South America immediately. stopping off at say the Egyptian pyramids, Abydos temple and checking out the latest discovery in Turkey of Göbekli Tepe on the way.
Here's the blurb of this excellent documentary: Join Researcher David Hatcher Childress and British Engineer Christopher Dunn as they journey to Cuzco in the Andes Mountains to examine evidence for the possible use of advanced rock-machining techniques. Going to ancient cities and megalithic quarries, they again examine saw marks, advanced lifting and moving techniques, as well as evidence of Pre-Incan megalith builders at Machu Picchu and Ollantaytambo. They continue on to Lake Titicaca where they investigate the strange megalithic towers and a "stargate" cut into solid rock. Finally they examine the huge granite megaliths at Tiwanaku and Puma Punku for signs of the use of power tools and other advanced, ancient technology. Blows the lid off South American archeology with evidence of advanced ancient technology thousands of years old.