We took a 4 day / 3 night Yangzi river cruise from Chonqing to Yichang, passing through the 5 level double ship lock (the largest ship lock in the word), which can raise or lower ships by 113 meters.
Large parts of the upper Yangzi river were submerged on completion of the Three Gorges Dam (180 m high / 2 km wide) creating a 645 km long reservoir.
othmar & wichit's space 