When have walls been used to keep people in, opposed to out?

by FreelancerWolfy
LegalAction

Circumvallation was a common siege technique in the ancient world. Possibly most famously successful at Alesia, where Caesar built a double wall to 1) keep Vercingetorix inside, and 2) keep Gallic reinforcements out. A failed attempt was the Athenian siege of Syracuse, in which the Syracusans managed to construct a counter wall to break the circumvallation (that is, they built a wall to interrupt the construction of the Athenian wall, preventing a complete encirclement). There was also a circumvallation at Plataea that was not too effective. The Spartans took the city but Thucydides reports a number of Plataeans escaped despite the wall.

estherke

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