No system of Castrametation ever devised by Polybius or Vauban could bear the slightest comparison with such vast fortifications, A city built on the floor of the circular cavity could be no more reached by the outside Lunarians than if it had been built in the planet Mars.
"All Around the Moon"
Jules Verne
No system of terrestrial Castrametation could equal these natural fortifications.
"The Moon-Voyage"
Jules Verne