• These maps of Cuba were provided by the US President Kennedy for the British Prime Minister at the time, Harold Macmillan.
  
• One map shows Cuba. The handwriting is by US and British government officials.
  
• The labelling of the map was based on photographs taken by American U2 spy planes. These aircraft flew at enormous heights and used sophisticated cameras to take pictures which had to be interpreted by experts.
  
• The other map shows the range of the different types of missiles which the US said were in Cuba.
  
• Nm stands for nautical miles, which are a little longer than ordinary miles (about 1.85 km)
  
• IRBMs are Intermediate Range Ballistic Missiles; MRBMs are Medium Range Ballistic Missiles.