Would you like to have a sip of 10-year-old pure drinking water?

Try the exhibition in Delhi to showcase various facets associated with the 3,000-year-old Zoroastrian religion.

The three-day exhibition at Ashok Hotel beginning Tuesday coincides with the two-day global conference called 'Dialogue among civilizations', organised by the Indian government in association with UNESCO starting Wednesday.

UNESCO has urged its member states to mark the 3,000th anniversary of the Zoroastrian culture this year.

The exhibition has a special significance as preservation of the dying Zoroastrian culture would be widely discussed at the global conference.

He said there would be a pictorial display of all Parsi traditions at the exhibition.

These include needle painting on clothes, carvings on wood, jewellery, paintings, photographs, ancient manuscripts and musical instruments.

"Parsi art and craft is an astonishing hybrid of the cultural traditions of Iran, India, China and Europe," said Lieutenant General A M Sethna (retired), a member of National Commission for Minorities and the man behind the exhibition.

But the most exciting exhibit would have to be the Tanka system of water harvesting that provides pure drinking water, which can preserved for over 10 years.

"For us, water is very sacred. The Tanka system of water harvesting is a Zoroastrian tradition that evolved centuries ago," said Sethna.

"It is now practiced only by the Parsis in a small village called Gulshan in Gujarat's Bharuch district; we came across it by chance."

"We were once in Gujarat and a group of Parsis served us water to drink. They told us the water we were drinking was 10 years old. I was surprised and asked them to explain," recalled Sethna.

In the Tanka system, rainwater collected on the roof is drained into a tank in the ground where it passes through layers of muslin cloth and gets filtered and purified.

"The roof is kept clean so that the rain water is not polluted. The tank is also not exposed to sunlight and care is taken to prevent growth of harmful microorganisms. The filter cloth is also kept clean," said Sethna.

"Water in these tanks could be as old as 10 years. It is pure and safe."

He said the Tanka water has been tested by the World Health Organisation, which declared it safe to drink.

The system was later exhibited in Japan while a group of experts from Delhi-based NGO Development Alternative studied it.

"The Tanka system came to India from somewhere in central Asia. We need to understand it better," said Sethna.

Pained by the decreasing population of Zoroastrians, Sethna is busy preserving and documenting everything about Parsis that he and his NGO Parzor Foundation could lay their hands on.

"Zoroastrianism is a religion that originated some 3,000 years ago in Iran and Parsis here are Iranians of Indian origin," said Sethna.

According to the 1991 census, there were about 71,000 Parsis left in India.

"Our population has been decreasing with every census. We are less than 0.01 per cent of the Indian population," said Sethna.

Parsis can also be found in Afghanistan, Uzbekistan, Tajikistan, Pakistan and Sri Lanka.

"Our most sought-after dish is Dhansak; made of dal and mutton. On special occasions, we add rice to it."

"Come and have it at the exhibition. We are offering 30 per cent discount for all those who show up in traditional Parsi dress," Sethna said.

More reports from Delhi