Ancient civilizations

123456
Across
  1. 3. Colosseum, gladiators, Roman Empire.
  2. 4. Pyramids, pharaohs, Nile River.
  3. 5. Great Wall, dynasties, inventions.
  4. 6. Harappa, Mohenjo-Daro, ancient cities.
Down
  1. 1. Tigris-Euphrates, cradle of civilization.
  2. 2. Democracy, philosophers, ancient Olympics.