It looks as if the wall was meant to end there but as soon as it was finished a second circleof battlements began to rise from the centre.
看上去好像这道围墙打算就此结束了，但它一完成，第二圈城垛开始从中心升起来。
2
(Modern designs include mechanisms for slowing traffic down as it nears the roundabouts, for example, and do not allow pedestrians onto the centreof the circle).