 In fact "twentieth" century explosive shells had some difficulty creating a breach in tamped earthen walls.Andrade goes on to question whether or not Europeans would have developed large artillery pieces in the first place had they faced the more formidable Chinese style walls, coming to the conclusion that such exorbitant investments in weapons unable to serve their primary purpose would not have been ideal.The city walls of Beijing, the last imperial capital of China, survived in substantially complete form into the 1950s.