Doraemon empty land with water pipes

Are you curious about the pipe in the Doraemon series, which is often the hangout place for Nobita and his friends? It turns out that the pipe is related to World War II. At that time, Japan's economic condition was unstable, so various infrastructure aids arrived, one of which was pipes from the United States.

In the 1960s the Japanese government intended to use the pipes to make drains and toilets. So that before use, the pipes are left piled up in the yard. Over time the pipes were used as a means of children's play.