Huludao, or Calabash Island, is actually a narrow strip of land extending about 100 kilometers east to west along the western seashore of the Liaodong Gulf. Its topography has earned Huludao the nickname "corridor of western Liaoning," with the city providing access from the three northeastern provinces of Heilongjiang, Jilin and Liaoning to central China and southeastern coastal areas. Jiumenkou Great Wall is the only section of the Great Wall over water. It is located in Suizhong county in Huludao and is the eastern portion of the Jizhen Great Wall from the Ming Dynasty. Jiumenkou Great Wall is an important pass in the Great Wall and is nicknamed the "first pass east to Beijing." It was built in 1381 in the early Ming Dynasty. It extends over 1,700 meters from north to south and the Jiujiang River runs beneath the wall. The riverbed built with large square stones is more than 7,000 square meters under the wall bridge.