Dalian is the third-largest city in China and one of the most important ports in the country. It has a special harbour dedicated to oil tankers. In the past, the city was occupied by the Soviet Union, which is why it has such an interesting and diverse international culture today. Dalian is said to be the most romantic coastal city of Northern China. Its architecture is influenced by both Western and Far-Eastern styles. Sights include: Sun-Yat-sen square in the town centre, the coastal promenade, the Museum of Marine Science, and Xinghai and Tiger Beach Park.