Where does Zhao Mengfu's Four Wonders "Dongcheng" refer to?

Personally, I think it may be east of Huzhou, Zhejiang, for reference only.

Zhao Mengfu was born in Xing Wu, Zhejiang (now Huzhou, Zhejiang). A famous calligrapher, painter and poet at the end of Southern Song Dynasty and the beginning of Yuan Dynasty, his grandson, a descendant of Qin Wang Zhao.

In the 23rd year of Zhiyuan (1286), Zhao Mengfu was recommended by Cheng Jufu, an imperial envoy of Taiwan, and was respected by Kublai Khan of Yuan Shizu. He has served as a bachelor in Jixian County, general manager of Jinan Road, a Confucian scholar in Jiangsu and Zhejiang, and a bachelor in Hanlin. Cheng Zhi, Bachelor of Hanlin, Doctor Rong Lu. In his later years, he gradually retired and then asked for help from his illness. In the second year of Zhi Zhi (1322), Zhao Mengfu died at the age of 69. He was named "Wen Min" by Pingzhang, Zhongshu Province, Jiangsu Province, posthumous title and Wei Guogong, hence the name "Zhao". He is the author of Song Xuezhai's Anthology and so on.