The Temple of Heaven in Beijing is a stunning place to see. I'm talking about the main temple here, not the entire park. There are smaller temples and buildings scattered around the park too, but the building you really want to see is the main temple.
The temple is surrounded by a giant courtyard so that anyone who wants to attend ceremonies can come. This design was incorporated throughout much of Chinese architecture to encourage people to gather and be together for community events. A sense that everybody is in this together is one of the main feelings I got on my initial travel through China. That is still the philosophy behind maintaining parks as gathering places and why so many parks are built around preserved historical landmarks and structures.
The inside of the temple is blocked off; for good reason, to keep the original interior preserved.