What's the name of a non-round coin?
A klippe is a square coin minted on more easily produced square flans either using round or square dies. These coins were originally issued under unfavourable conditions, such as a city under siege. Such emergency coins were issued in Vienna in 1529, while the city was besieged by the troops of the Ottoman Empire.
Answers by country
the United Kingdom
the United States
In World War II, a Nazi submarine U-1206 was accidentally sunk by?
A sub-sea landslide
An improperly operated toilet