I strongly disadvice you to take any guided tour to the Great Wall from the tour operators that operate in the Forbiden City.
When visitng the Forbiden City, we were approached by a guy who called himself “Bill”(that was suposed to be his english name though he was a chinese). He offered us a tour to the Great Wall plus Ming Tombs. Because we anyway wanted to see it, we arranged it.
On a day of tour his van came to pick us at the hotel. Beside driver there was a woman who introduced herself as our guide. A first supprise(when we were already on the motorway) was when she told us that we wouldn’t be visiting Ming Tombs. Apparently, because of the clousure on the motorway we would be forced to go via side roads and this would cause a delay and blah blah… We protested for a moment but we got along with it. Anyway it was said to us, this is merrely a park.
Before we got to the Wall, we unexpectedlly stoped at a “factory” in one village. She said we should go inside although it was not on the program. We didn’t wanted to, because we heard many stories of people being forced to buy something in such “factories”. She then even got angry and threated that she will leave us there in the middle of nowhere alone if we do not go inside. This was even more suspicios to us and when she realized that she won’t succeed, we continued driving to the Wall.
When arriving at the Wall we entered the cable car and went atop. She didn’t go with us but promissed to pick us at the parking some hundred metters before the entrance, a few hours later. When we arrived at the top she called us via mobile and said she wouldn’t be back and she would leave us there. This was obviously a revenge for not visiting that bloody “factory”. When we protested she began to blackmail us, saying she would come back to pick us but we would have to visit that “factory” and also go to a kind of tea degustation. There was time to do this but not obviously for the Ming Tombs being originaly on the program. And we of course heard the stories about degustations which costed the participants lurked into it, even up to 50 or 100 euros. So we smoothly denied it.
Luckilly, there were taxis near that parking which drove us to the nearest city when we were able to take the bus back to Beijing.
So under any condition, do not take anyone offering you a tour to the Great Wall in the Forbidden City or around.