The world’s largest dam re-opened its gates to visitors last month and we were among the first to check out this almost completed man-made wonder.

Initially opened to tourists in 2005 the Three Gorges Dam (TGD) was closed at the end of 2007 because of security fears.

This was also the explanation given for why we have to take a government registered tour bus to the site, near Yichang in Hubei province.

Easy to organize and costing 150 yuan ($22), the coach zips through a series of checkpoints but getting through the main entrance is reminiscent of checks at a major airport.

The TGD complex includes a park, information center and viewing platform of the site, including the record-breaking locks and ship lifts. There are plans to build a hotel complex.

Despite the rain and limited visibility it’s not hard to appreciate what a monumental construction the dam is.

At 2.3 km long and 185 m high, it’s a mind-boggling amount of cement. Comparisons with the Great Wall are apt.

“The mountain goddess if she is still there/Will marvel at a world so changed,” was former Chairman Mao Zedong’s poetic vision of the project, in 1956.

Costing $22.5 billion the dam will produce the same amount of electricity as 15 large nuclear power stations, and create a lake half the length of California.

Unlike the Wall, it can be seen from space.