Construction of the Kaohsiung Cross-harbor Tunnel, the first submarine tunnel in the Republic of China, began in May 1981. It started from Chien-chen Fishery Harbor, across the fairway of the Port of Kaohsiung, to Chi-chin Island south of Kaohsiung. The project includes 1,550 M. of main tunnel and approaches. The main tunnel is designed and constructed as a dual two-lane tunnel, which includes six unit-tubes, each 120 M. long. After three years' construction, the Tunnel, with a total cost of some four thousand million NT Dollars, was opened to the public on May 18, 1984.