Discovery Channel's Behind the Great Wall

I watched the 2-hour special called "Behind the Great Wall" on 1/27/2008 on the Discovery Channel. It was rather interesting, both in its portrayal of people and events. It claimed to show sections of the wall not captured on film before. It also explained things in ways very different from what I know of the Great Wall. Shows how flawed my knowledge of Chinese history is. :-p

Some points:

• Language: All of the dialog was in English. This was a bit odd, I think, especially since in some of the scenes you can clearly hear the cast talking in Chinese. All of the speakers had no significant accent when speaking English either. I think it was odd, but it worked fairly well.
  
• Chinese cannons: The documentary claimed that there were cannons used, and the design was imported from the West. I wasn't sure when contact with the West happened and I didn't know cannons were already in use by then.
  
• Mongol raiders: There were no Mongol archers depicted, which was what the Mongols were known for. I speculate that's because mounted archers would greatly complicate filming.
  
• Timing: The documentary covers the events in the Ming dynasty (明朝), focusing on 戚繼光. (Explanation thanks to my friend Kai-ping.) I had always thought that it was 秦始皇 who is credited for the Great Wall.

Well, all in all I think it was an educational special without being too cheesy.