30 years later, the DPRK is considered "backward" by the Chinese. Nevertheless, Dandong changed a lot, and for the better.

"In my opinion, the DPRK has not changed over the past 30 years, except for several small buildings opposite from us. The old paper mills and shipyards are still set in their old ways," Chang said.

Taxi driver Liang often takes tourists to the Dandong Riverside Avenue. He likes to show the tourists the avenue and then point to the opposite side. "If you come here in the evening, the lit-up avenue will be more beautiful."

In Liang's memory, the riverside avenue was packed. At first, small piers and small shipyard buildings were scattered all over the area. They were renovated after the reform and opening up. The formerly unattractive waterfront housing area has now become one of the most expensive areas in Dandong, with some buildings boasting a price of over 10,000 yuan per square meter.

Time has brought great change to Dandong. In the 1970s, it was nearly the same as the DPRK's Sinuiju. Now both cities are totally different from each other. "If the DPRK can open up to the outside, Dandong will be another Shenzhen in China, or even better."

Huangjinping Economic Zone's growth is a slow process

In comparison with North Korea, the people of Dandong usually have a great sense of accomplishment. Nonetheless Dandong remains a bit "backward" in terms of its total economic output from a national perspective, or in comparison with other cities in Liaoning Province.

For a long time, in terms of GDP, Dandong has ranked about the fifth from the bottom among the 14 cities in Liaoning. In 2012, Dandong's GDP, for the first time, exceeded 100 billion yuan, a great achievement for the Dandong government.

In 2006, Dandong, inspired by other cities in China, began to develop itself through the construction of the new urban area. Therefore, an area of 117.96 square kilometers was constructed.

By the end of 2010, the construction of the New Yalu River Bridge began. On June 8, 2011, the project of the Huangjinping Economic Zone and the Granville Island Economic Zone, jointly developed by China and the DPRK, were officially launched. Dandong wanted to get the three construction projects "packaged," aiming to become an important economic zone in northeastern China.

"Such intensive infrastructure construction is rare for China," said Shi Guang, mayor of Dandong, in his yearly government work report.