Season 1 National Geographic , 2014 Watch now Season 2 National Geographic , 2015 Watch now Season 3 National Geographic , 2016 - 2017 Watch now Season 4 National Geographic , 2017 Watch now Season 5 National Geographic , 2017 - 2018 Watch now Season 6 National Geographic , 2018 Watch now Season 7 National Geographic , 2019 Watch now Season 8 National Geographic , 2020 Watch now
, 2014
, 2016 - 2017
