There are two ways to do the great wall. Hitting the tourist areas which are cleared out, easy access and involves a cable ride up and taking a ride down to the bottom via a toboggan OR hitting an abandoned area with a guide.
We chose the abandoned hike route.
The hike was 7-8km long and not the easiest. A fit family, but when it is 35C (+humidity), not a cloud in the sky and the first 1.5km involves an elevation change of 800 meters, your fitness is tested (Actually, the other 3 did fine, the only one tested was me). Fortunately, our guide provided the right amount of instruction on quantity of water and ensured that we brought enough food.
I will say that about half way up with a backpack full of bottled water, my Canon 5D Mark III, the 28-300mm f/2.8 lens and a 50mm lens stored in my pack (Why a 50mm? No idea), I was wondering if I should have packed a bit lighter.
Our starting point was at what use to be a resort hotel of some type – no longer.
The chicken coop at the start of the hike.
The trail up is a mix of steps (In a few of the steepest places) and rough hiking trails – at a 45 degree or steeper angle. The math makes sense, 1.5km, 800m elevation. Clearly not over-used. In our 7-8 hour hike, we saw 2 other people who were on a hike with their dogs.
As we stopped, we took the time to look back over the valley. Beautiful views and a clear day. A stark contrast to the polluted Beijing sky.
It is a long way up but very satisfying when we came around a corner and the wall came into sight.
Our destination where we will break out lunch.
A good start.
Michael Weening: a few pictures 
Your pictures are gorgeous! I love this idea and I think that’s the way I’d prefer to go about it too… any advice on finding a good guide for the trip??
Thanks Jess. My advice is trip advisor. We used Stretch-a-leg travel. They were very good for this portion of our travel (this hike is their specialty).
Fantastic, thank you so much!