Take a tour through the great siege tunnels built during this time.

参观当时建造的这座大围攻坑道。

They remain one of the most impressive feats of military engineering and helped the English to a seemingly impossible victory.

这些坑道至今仍是最令人印象深刻的军事工程之一，帮助英国人拿下了这场似不能达成的胜利。

They also used a technique called undermining, or digging tunnels under the walls then setting fires in them to cause the walls, which had timber frames, to collapse.

他们还使用了一种叫做挖坑道的技术，就是指在城墙下挖隧道并在其中放火，导致木的城墙倒塌。

Its tunnels were built using a method known as cut-and-cover, where rather than boring a tunnel through the ground, instead, a massive trench is dug, the railway built, and then the trench roofed over again.

地铁隧道是明挖覆盖式工法兴建，不直接挖穿地面，而是挖掘坑道、兴建铁路轨道，再将地面回填。