Abandoned Engineering: Season 5, Episode 4

5 - 4: Top Secret Nuclear Arsenal

Including an exploration of a secretive underground base that concealed the power to destroy nations; Willamette Falls, a sprawling industrial relic clinging to the edge of an unforgiving waterfall; strange constructions, separated by a century, but joined together by war; and Pilgrim's Rest, a hauntingly silent town lost deep in hills of South Africa.