Quieter than Badaling with the same iconic towers
Mutianyu is the Great Wall section first-time visitors in the know pick over Badaling: the same Ming Dynasty (1368-1644) stone, 23 restored watchtowers over 5.4 km, and noticeably fewer tour buses. On a clear weekday morning you can stand alone on a watchtower with the entire ridge curling into the distance - a feeling Badaling rarely offers.
Five-hour ridge traverse for serious hikers
From south gate, take the south stairs 30 min up to tower 6, then east to tower 1 (Dajiao Lou, the eastern high point), back to 6, and west to tower 23 (Desheng Tang, the western end). The full traverse is 11 km with 966 m of elevation gain, 6 hours, and almost every watchtower on the wall. Cable car or toboggan at either end if you want to shorten it.
The 1.2 km toboggan slide back down
After all that climbing, the toboggan run from tower 6 down to the south gate is the reward: a handbraked stainless-steel sled on a 1.2 km chute, you control the speed, and the kids (and adults) end the visit screaming with laughter. The combined cable-car-up + toboggan-down ticket is about CNY 140, sold at the south gate.