Outside the east gate of the Hall of Praying for Good Harvests (Qiniandian) in the Temple of Heaven, a long corridor stretches, with red-painted columns, green glazed tiles on the roof and connected eaves and ridges. Along the corridor there are 72 conterminal rooms, also known as 72 Lianfang.

Measuring about 5m in width and 300m in length, the long corridor was constructed in 1420, the 18th year during Emperor Yongle’s reign in the Ming Dynasty. Such a large corridor can be rarely found in ancient architectures. Different from other corridors winding through gardens, the corridor does not have colorful decorations or patterns of dragons or phoenixes painted on it. All colored drawings on it use cold colors such as black, white, cyan and green. They are in the painting style Xuanzi Caihua, a traditional one adopted in Chinese ancient architectures, which uses only inked lines instead of gold decorations and paints flowers with blue, green, black and white colors. The drawings, despite being simple, are dignified, graceful and solemn. The corridor served as a passage for oblation transport. In order to protect the sacrificial offerings from being tainted by rain, snow, wind or sand, the corridor was originally equipped with front windows and rear walls.