14 Mysterious Landmarks That Science Still Can't Fully Explain

13. The Gates of the Sun and Moon (Tiwanaku, Bolivia): Celestial Alignments and Lost Techniques

Located near Lake Titicaca, the ancient city of Tiwanaku is home to the Gate of the Sun and the Gate of the Moon, monumental stone arches carved from single blocks of andesite. Dating back to the Tiwanaku civilization (c. 500-1000 CE), their intricate carvings depict mythical figures and celestial symbols. The Gate of the Sun, in particular, is believed to be an astronomical calendar. However, the exact methods used to carve these massive, hard stone structures with such intricate detail and precision using pre-Inca tools remain a profound mystery. Their astronomical function and advanced stonework continue to baffle scientists.