LUCERNE, Switzerland — From the outside, the Sonnenberg nuclear bunker looks innocent enough: its entrance is in the middle of a children's playground. Rob Schmitz / NPR The entrance to the nuclear bunker underneath the University of Bern's History Department building. If a nuclear war between the U.S. and the Soviet Union were to happen, Swiss officials reasoned at the time, Switzerland — an historically neutral nation — would likely not suffer a direct hit. The country has more than 370,000 nuclear bomb shelters. And that's part of the reason why in 2002, Switzerland's government reduced the Sonnenberg bunker capacity from 20,000 to just 2,000.