It’s called the Lama Temple and it’s supposed to be the main Buddhist Temple in the Beijing area. I’m not sure if that’s true or not, but I do know that it’s on all of the main-list-of-attractions for virtually every source I checked. What’s going on in the picture is that people are praying/worshiping and burning incense. They had to burn it outside as they weren’t allowed to burn it inside the temple. It made for some interesting fragrances.