Sancha He, marketed as the "Wild Elephant Valley", sits about an hour north of Jinghong on the road to Pu'er. The park covers a stretch of natural rainforest at the southern edge of the wild elephant range — China's roughly 300 wild Asian elephants drift in and out of the reserve, and there is a real (though not guaranteed) chance of seeing them from the elevated walkway that runs above the forest floor.
What you will see for certain are the captive elephants in the reserve's training centre, who perform daily shows of a somewhat outdated kind. If that is not your thing, skip the show and walk the canopy path early in the morning, when wild elephants are most likely to be near the river. Watchtowers along the trail give a better chance of a sighting.