The Hall of Preserving Harmony is a palace-style building in the Forbidden City in Beijing. The existing main beam frame is still a Ming Dynasty building. The Hall of Preserving Harmony is 9 bays wide and 5 bays deep. The roof is a double-eaved hip roof covered with yellow glazed tiles, and 9 small beasts are placed on the upper and lower eaves. The floor of the hall is paved with gold bricks, and a carved gold-painted throne is set up facing north and south. The east and west ends are warm rooms. The building adopts the method of reducing columns, and six golden columns on the front eaves of the hall are reduced to make the space spacious and comfortable. In the middle of the rear steps of the Hall of Preserving Harmony is a royal road stone carved with clouds, dragons, sea water and cliffs, which people call the cloud dragon stone carving. Every rainy day, there is a spectacular sight of thousands of dragons spitting water. The thousands of dragons refer to the more than a thousand stone dragon heads extending from the bottom of the pillars. Every rainy day, rainwater is discharged from the dragon's mouth, so that the practical function of diverting rainwater is organically combined with the ornamental function of architectural art. The verandas on the east and west sides of the Hall of Preserving Harmony have now been turned into exhibition halls.