The second undersea tunnel of Jiaozhou Bay in Qingdao City, east China's Shandong Province is underway on March 8, 2026. The tunnel is the world's largest undersea tunnel in terms of construction scale, the longest of its kind, and among the most technically challenging. (Photo provided to China News Service)

The second undersea tunnel of Jiaozhou Bay in Qingdao City, east China's Shandong Province is underway on March 8, 2026. The tunnel is the world's largest undersea tunnel in terms of construction scale, the longest of its kind, and among the most technically challenging. (Photo provided to China News Service)

The second undersea tunnel of Jiaozhou Bay in Qingdao City, east China's Shandong Province is underway on March 8, 2026. The tunnel is the world's largest undersea tunnel in terms of construction scale, the longest of its kind, and among the most technically challenging. (Photo provided to China News Service)