Share: Title:Portland's Forgotten Tunnels & Trapdoors (Shanghai Tunnels Explained) Duration: 15:38 Plays: 70K views Published: 2 years ago Download MP3 Download MP4 Simillar Videos ▶️ 21:14 How The Erie Canal Transformed America - It's History 70K views • 2 years ago ▶️ 24:53 What Happened To America's Oldest Telephone Network? (history Of The Telephone) - It's History 70K views • 2 years ago ▶️ 19:14 The Rise And Fall Of Bisbee Arizona - It's History 70K views • 2 years ago ▶️ 14:58 When Seattle's Underground Became Infested With Criminals And Rats (literally) - It's History 70K views • 2 years ago ▶️ 15:19 New York's Weirdest Building - Lost Forever - It's History 70K views • 2 years ago