If you're in Beijing, you MUST see the Great Wall. I've researched a lot on which part of the wall my family and I should visit and I chose the Mutianyu side. It's true that it isn't as crowded as the Badaling side and you get to have the wall all to yourself. It was an amazing feeling to be walking on one of the man-made structures that can be seen from outer space. I haven't been to the other parts of the wall, but based on what I've read, and I agree with them, the Mutianyu gives you the best of both worlds. You get to see the original wall and the restored wall and the hike isn't as bad as the Simatei side.

Make sure you take the lift going up and the tobogan going down. It's a lot of fun! The lift is a lot like taking a ski lift so don't be surprised to see your feet dangling several meters off the ground! And although the tobogan looks dangerous, I realized later on, it wasn't dangerous at all because you control how fast you want to go.

A lot of vendors will greet you on your way down. Look at their products from afar first before you approach them. Once you go into a store you'll have a difficult time getting away from the vendor so make sure you like what you see before you start haggling.

We booked a private tour over the internet through beijingservice and they were very pleasant and accommodating. I highly recommend this!