Siege weapons and defense weapons in ancient China

May 2019
I admit that I don't know if this is possible, but there are some bigger gaps between stone blocks, so maybe it's possible for arrows to stuck in those gaps?

Anyway, I'm translating subtitles to my language from English subtitles, that's why I would like to know if there is an English name for that defensive device with big rock, because it doesn't look like Malevolent Wood. If there is no English name, I will just simplify translation to "defensive devices".