The Forbidden City, the largest ancient architectural complex in China, attracts countless tourists with its grand scale and exquisite artistic style.
You may not know that there is a remarkable phenomenon regarding the roofs of the Forbidden City: they have never been contaminated by bird droppings and remain clean all year round. This phenomenon may surprise many people and even make them skeptical.
Why are there never any bird droppings on the roofs of the Forbidden City? The answer to this question actually relates to various aspects such as ancient Chinese construction technology and environmental protection.
The Forbidden City is the largest ancient architectural complex in China.
One of the mysteries that piques the curiosity of visitors to the Forbidden City is the fact that the roofs here are always clean, rarely showing any signs of bird droppings. Unlike other architectural works, which, despite regular cleaning, still struggle to avoid the “visits” from these uninvited guests.
What we need to understand is that the architecture of the Forbidden City is very unique. Its roofs are not flat or sloped like those found in typical buildings today, but have a special shape known as “curved eaves.” The shape of these roofs resembles a gigantic hat, wide at the bottom and tapering to a point at the top.
This design makes it difficult for birds to perch on the roofs. When tired, birds tend to seek out flat surfaces to rest on, while the upper part of the eaves in the Forbidden City tapers, making it hard for birds to land there. Even if some birds accidentally land on the roof and “do their business,” the droppings will quickly slide off due to the shape of the roof.
Most roofs in the Forbidden City are curved, forming sharp angles. This design makes it difficult for birds to perch and stand, thereby minimizing the likelihood of bird droppings on the roofs.
Another feature of the roofs in the Forbidden City is that they are all made of yellow glazed tiles. This type of glazed tile not only has a bright color but also a smooth texture. While flying, birds tend to choose darker and rougher surfaces to land on as this reduces their risk of slipping. Therefore, birds are inclined to avoid the yellow glazed tiles when searching for a place to land, thus reducing the chances of droppings falling on the roofs.
In addition to these two reasons, the absence of bird droppings on the roofs of the Forbidden City is also related to ancient Chinese building technology. In ancient times, builders used a special method to prevent birds from nesting on the roofs. Specifically, they would place some fake bird nests on the rooftops to attract birds to nest there. Once the birds built their nests on the fake ones, the real nests would be removed. This way, birds would not nest on the roofs, reducing the chances of droppings falling onto them.
The roofs are covered with a special smooth glaze. This smooth surface makes it difficult for bird droppings to adhere and allows them to be easily washed away by rain or wind.
From ancient times, the ancient Chinese placed great importance on protecting the natural environment. They believed that humans should live in harmony with nature rather than destroy it. Therefore, when building homes, they sought to avoid causing harm to the natural environment. For example, they would try to choose locations for construction that did not attract birds, and when building, they would minimize their impact on the environment. This awareness of environmental protection also resulted in very few bird droppings falling on the roofs of the Forbidden City.
In science, there is a theory known as “fluid dynamics” that can explain why there are no bird droppings on the roofs of the Forbidden City. This theory suggests that all moving objects are affected by air resistance. Birds are no exception when they are flying. As birds approach the roof, they sense the impact of the airflow against the roof. If the roof surface is too smooth, birds will experience significant air resistance, making them reluctant to land. Due to the use of yellow glazed tiles and the design of the curved eaves, the airflow around the roofs of the Forbidden City becomes more streamlined. Thus, they tend to avoid these roofs, further reducing the likelihood of droppings landing on them.
Historical records suggest that hawks were once bred in the Forbidden City to hunt small birds. This helped to limit the number of birds in the area, thereby minimizing bird landings and droppings on the roofs.
The combination of various factors, including intelligent architecture and deterrent measures, has contributed to this remarkable phenomenon. This mystery further enhances the allure and value of the Forbidden City, making it a must-visit destination for those who appreciate Chinese history, culture, and architecture.
