By Frances Harrison
BBC News, Tehran
A new dam is due to open in southern Iran amid criticism it will flood an ancient site holding archaeological relics dating back 7,000 years.
Sivand dam is a massive project that will benefit many farmers
The government says the Sivand dam in the Bolaghi gorge is needed by farmers in an area that has become desert.
Heritage activists have appealed to the president to postpone the flooding by some years so excavation can continue.
Archaeologists have discovered ancient wine making vessels, clay kilns and prehistoric caves in the area.
Many relics have been removed to be placed in a museum, but the site itself will be flooded which conservationists argue will be a huge loss.
But the government's going ahead with the inauguration of the dam because farmers in the area desperately need water for irrigation.
There has been much confusion about exactly what damage to Iran's ancient sites the Sivand dam will do.
Archaeologists, including foreign teams, have been working to excavate remains in the gorge that is to be flooded.
They found pools and clay pots belonging to an ancient wine workshop, though today grapes no longer grow in the area.
And 7,000 year old clay kilns have been unearthed, along with prehistoric caves and a unique seven-kilometre stone boundary wall that some believe once enclosed a hunting ground 2,500 years ago.
What has worried some experts is that the dam is very close to Cyrus the Great's tomb and his palace, monuments honouring the founder of the Persian empire.
Some experts argue that the dam will increase humidity in the area, sharply exacerbating an already serious problems with lichen eating away at the 2,500-year-old stones.
The controversy of the Sivand dam has highlighted the bitter struggle between those who want to modernise and develop Iran at any cost and heritage experts who want society to place a greater value on the country's rich ancient heritage and do more to preserve it.