The excavation of a mountain castle in central Turkey has revealed a secret tunnel, built by the Hittites around 4,000 years ago. Geval Castle, on Takkel Mountain in Central Anatolia, sits over 5,500 feet above sea level and once offered a strategic 360-degree vantage point for a population that regularly faced assaults from the Egyptians, Assyrians, and Thracians throughout their history. As a result, Hittites were master underground builders, although the exciting discoveries at Takkel Mountain appear to be the first of their kind. "We have discovered secret tunnels in the castle. We have cleaned there and revealed a [328-foot...