![Robot discovers three unexplored passages in 2,000-year-old tunnel near the Pyramid of the Sun in Mexico | Daily Mail Online Robot discovers three unexplored passages in 2,000-year-old tunnel near the Pyramid of the Sun in Mexico | Daily Mail Online](https://i.dailymail.co.uk/i/pix/2013/04/23/article-2313312-19703244000005DC-283_1024x615_large.jpg)
Robot discovers three unexplored passages in 2,000-year-old tunnel near the Pyramid of the Sun in Mexico | Daily Mail Online
![Robot discovers three unexplored passages in 2,000-year-old tunnel near the Pyramid of the Sun in Mexico | Daily Mail Online Robot discovers three unexplored passages in 2,000-year-old tunnel near the Pyramid of the Sun in Mexico | Daily Mail Online](https://i.dailymail.co.uk/i/pix/2013/04/23/article-2313312-196FFBD6000005DC-334_634x388.jpg)
Robot discovers three unexplored passages in 2,000-year-old tunnel near the Pyramid of the Sun in Mexico | Daily Mail Online
![Robot discovers three unexplored passages in 2,000-year-old tunnel near the Pyramid of the Sun in Mexico | Daily Mail Online Robot discovers three unexplored passages in 2,000-year-old tunnel near the Pyramid of the Sun in Mexico | Daily Mail Online](https://i.dailymail.co.uk/i/pix/2013/04/23/article-2313312-1970128F000005DC-425_634x336.jpg)