40 Tonne vault door that could be moved with one finger.
Giant underground water tank in Tokyo used with the to help control flooding – 177 meters (580 feet) long and 22.4 meters (73 feet) high
Bomb shelters never seem to go out of style – This article documents several people and organizations that have constructed large bomb shelters. The writer spends a night in an underground shelter and concludes that they aren’t for him. His article sheds a slightly negative view on the long term viability of shelters.