From one amazing phenomenon to another, but this time a man made one. The Itiapu Dam is a joint venture between Brazil and Paraguay and dams the Parana River on the border between the two countries.

Like the Iguazu Falls the statistics are impressive. It is 7.2km long and 225m high. The lake it created is over 100km long and 7 km wide. It can generate 14,000 megawatts of electricity - perhaps enough to supply the electricity needs of over 10 million European homes. Certainly the dam generates enough electricity to meet over 80% of Paraguay's needs and 15% of Brazil's. It does this through 20 huge turbines in a generator hall that is 1 kilometre long.

It was selected by the American Society of Civil Engineers as one of the Seven Wonders of the Modern World but is no longer quite the biggest having recently been surpassed by the Three Gorges Dam in China. However it remains the most efficient hydro-electric power plant as the Parana River flows consistently throughout the year.

Most remarkably, perhaps, it was conceived as long ago as the early 1960s when some far-sighted Brazilian engineers realised that the country needed a reliable source of power. At that time both Brazil and, especially, Paraguay were relatively poor and undeveloped countries (Paraguay still is) so for them not only to agree to build it but to actually complete it was a significant feat. It remains, perhaps, a relatively rare instance of mutual co-operation between two countries over the use of water resources. The border runs right through the central control room so on a visit you cross and recross between the two countries with not a border post or immigration officer in sight (although for the trip into the dam itself security is very tight.)

In environmental terms it is reckoned that the electricity produced by the dam is equivalent to burning about half a million barrels of oil a day. However because of its sheer size (enough concrete to build 15 Channel Tunnels) its construction will have had a significant negative impact. Not to mention that upwards of 40,000 people were displaced by the reservoir, 700 square kilometres of rainforest destroyed and the Sete Quedas falls, which rivalled Iguazu, were completely submerged. Some commentators also claim that it has held back the development of Paraguay as the country chooses to sell much off its share of the electricty back to Brazil, as an easy source of foreign exchange, rather than use it to power its own economy.

Whatever the real truth it is just as awe inspiring as the Iguazu Falls in terms of its engineering and construction and counts as one of the most remarkable places that I've visited.

(A word of explanation is required. For the heading for each of my blogs I'm trying to use a song title. Today's is a song by Gorillaz. I think i may struggle to keep this up for the whole trip!)