picpac19 on Instagram: "China has completed the Shenzhen–Zhongshan Link, a 28 km cross-sea corridor connecting Shenzhen and Zhongshan across the Pearl River Estuary. The project combines long-span bridges, artificial islands, and a 6.8 km immersed tube tunnel beneath open sea waters. The eight-lane tunnel is among the widest ever built, cutting travel time from nearly 2 hours to just 20–30 minutes. Engineers used prefabricated tunnel sections, precisely lowered and sealed on the seabed, while ad