1 of 8
After 10 years of construction, the sluice gates of China's massive Three Gorges dam have finally been closed

2 of 8
The reservoir behind the dam can now start filling up with water, to create the world's largest hydroelectric project

3 of 8
The project, which will create a lake 600 km (375 miles) long, is surrounded by controversy

4 of 8
China hopes the dam will stop the catastrophic flooding of the Yangtze river, as well as providing much needed electricity

5 of 8
But more than 600,000 people have already been forced to leave their towns and villages to make way for the reservoir

6 of 8
Some went back on Sunday to say a last goodbye before their former homes were submerged in water

7 of 8
Critics also say the $25bn project will cause huge environmental damage

8 of 8
And for the many people who make their living on the river, the dam will force them to look for a new livelihood