article_snippet.sent: archaeologist hunting for a royal tomb in a tunnel .
article_snippet.sent: the end of a sacred tunnel sealed for nearly 1,800 years.
article_snippet.sent: the entrance to the tunnel below Teotihuacan's Pyramid of the .
article_snippet.sent: archaeologists work at a tunnel that may lead to a royal tombs discovered at the ancient city of Teotihuacan in 2011.
article_snippet.sent: archaeologist Sergio Gomez's six-year slog in a tunnel that may lead to a royal tombs discovered at the ancient city of Teotihuacan in 2011 has already yielded tens .
highlights_snippet.sent: chamber of Teotihuacan pyramidhad been sealed at the end of a tunnel for nearly 1,800 years .
  