eli5: Why were some ancient cities like Palmyra and Machu Picchu left to ruin and fall apart over hundreds of years instead of being repopulated?

Question

eli5: Why were some ancient cities like Palmyra and Machu Picchu left to ruin and fall apart over hundreds of years instead of being repopulated?

In: 1677

Answer 1

When a culture is annihilated survivors tend to flee. If they are able to reproduce, they warn their children about the dead cities and create superstitions as to why they should never return. Sometimes this is practical to avoid whatever destroyed the city in the first place. Worse yet, there may not be anyone left alive who remembers the city and it is consumed by the forests. Westerners are lucky to find what’s left of these metropolises.