The Wuhan Yangtze River Tunnel, opened in 2008, was the first tunnel ever bored under the Yangtze and a piece of engineering trivia worth noting if you are interested in Chinese infrastructure. It runs from Hankou to Wuchang under the southern part of central Wuhan, carrying two lanes of traffic in each direction.
There is nothing to see — it is a tunnel — but for anyone driving across the city it is the fastest way over the river at peak hours and worth experiencing once. The Wuhan metro also has multiple subaqueous lines under the Yangtze, also among the first of their kind in China.