Lost in Heaven: Man walking across the Temple of Heaven seems to be lost -- who wouldn't be with the size of the temple complex. The Temple of Heaven covers an area of about 2,700,000 sqm and is larger than The Forbidden City (another magnificent structure in Beijing worth visiting - both of which by the way were built and completed around 1420). The temple is actually a sacrificial altar and was primarily used by Emperors to worship heaven for good harvest. The ceremonies were held there until late 19th century (I think) and was therefore not open to public during that period. This site was declared a UNESCO Heritage Site due to its importance in the evolution of architecture in China.
Some photo-taking notes: Go in the morning if you want to catch the locals doing Tai Qi, Kung Fu, dance, etc. in the park. Since it's a must-see attraction when in Beijing, it will be really difficult to photograph the temples without the tourists being included in your shot. Your best shot (no pun intended) is very early in the morning on weekdays.