One of my very first WHS in 2006, the Temple of Heaven is one of the premier examples of Chinese traditional architecture. The exquisite wooden structure is one of a kind, and the wide circular layout of the grounds, which include dozens of unique stone carved images along stairways, large swaths of green space, and on less busy weekdays an atmosphere of sacredness.
Almost all of the Beijing WHS are extremely busy during weekends (or holidays), and if you have to jostle for space your visit might not be pleasant! A key stop for any visit to Beijing, the Temple of Heaven is a WHS that preserves some of the historic fabric of Beijing that over time has diminished to some degree. As a key historic site of the Central Axis of Beijing, the Temple of Heaven is certainly worthy of its world heritage status alone.