The Iron-Dragon airboat slowly declined in a huge grain-sunning ground outside a fortress at the riverside of Ninghe River.
It was Ninghe Fortress which was responsible for managing all the official fields in Ninghe Prefecture.
In Ninghe Prefecture, the universal airport was not required as all the grain-sunning grounds being attached to each farm or fortress being paved with cement or stones which were hundreds of meters in length and width at least. These grain-sunning fields were natural universal airports in Ninghe Prefecture.
Zhang Tie saw a lot of people waiting for him on the grain-sunning fields, some were in eye-catching red, blue and purple uniforms.
"Why have the officials of Ninghe Prefecture arrived here?" Zhang Tie asked Donder.