The site of Pumapong Valley in the ancient city of Tiwanaku was built about 20,000 years ago and has now collapsed. Now there are only fragments of boulders everywhere, each of which is about several hundred tons. They are cut very smoothly and neatly, even to their hands. If you want to polish them, you must use diamonds. Stones of the same depth.

Grooves several millimeters deep, and the lines formed by these grooves are straight. Judging from the signs of collapse, the architectural structure of the temple, like building blocks, is made of huge stones. These stones are very hard, and the joints between them are connected like bumps and grooves. There is a square slate with a very smooth surface near the site, which has not been damaged at all after thousands of years.

With the concept of modern people, it was impossible to build such a seamless boulder building at that time.