Building Wonders Feb. 25, 2015: Hagia Sophia: Istanbul's Mystery Feb. 18, 2015: Petra: Lost City of Stone Feb. 11, 2015: Colosseum: Roman Death Trap Jan. 28, 2015: Sinkholes—Buried Alive Jan. 21, 2015: Sunken Ship Rescue Nov. 12, 2014: Emperor's Ghost Army Feb. 12, 2014: Great Cathedral Mystery Feb. 6, 2013: Building Pharaoh's Chariot Oct. 10, 2012: Secrets of the Viking Sword Oct. 5, 2011: Building the Great Cathedrals Nov. 16, 2010: Secrets of Stonehenge Feb. 2, 2010: Ghosts of Machu Picchu Jan. 19, 2010: Riddles of the Sphinx Apr. 8, 2008: Cracking the Maya Code Jan. 29, 2008: Secrets of the Parthenon