BBC News, Dhaka
The sewers of Dhaka, Bangladesh's overcrowded and polluted capital city, are as unpleasant as you could imagine.
But they are also an incredible source of income for a small group of men who do not mind getting their hands dirty.
They earn their living by finding tiny specks of gold that are accidentally brushed into the open sewers that run alongside the narrow streets of Dhaka's historic gold bazaar.
With the price of gold hitting $1,000 an ounce for the first time earlier this year, these specks are worth more than ever before.
The men pan for gold in the drains in exactly the same way as the treasure-seekers of the legendary Californian gold rush of the 1850s.
Mohammed Harun gave me a demonstration. He swirled his pan around, full of dirty black water, stones, sand and other matter. Then, he gently isolated bits he wanted a closer look at, using his orange-brown stained fingers.
"I used to think that this work was really nasty," he said. "But I'm used to it now, its just my job, and it brings me money."
The morning I met Harun, he reckoned that he and his two friends, who all work together as a team, had found about $50 worth of gold, as well as some small bits of silver and even a tiny red jewel.
It is no fortune, but it is enough for the three men to feed their families for several days.
There are 350 gold shops and workshops in Dhaka
"Today we've had some luck. We cannot work much during the monsoon as when it rains the sewers are washed clean," he said.
Further along the street, Salahuddin, an older man with white hair, was working alone. He crouched low over the stinking drain, and with one hand scooped out mud in a small metal bowl, and with the other took rapid puffs on a cigarette.
"I earn about $12 a day looking for gold like this, and if I'm lucky I'll also find some ear-rings or something else that people have dropped down here," Salahuddin said.
As he worked, a pipe carrying waste from somebody's bathroom emptied into the sewer and upstream a man urinated.
Meanwhile, over the road, boys in white caps gathered at the door of their religious school, men walked past with baskets of pineapples on their heads, and Hindu shopkeepers lit incense and muttered prayers.
The street is called Tanti Bazaar, and it is the centre of Dhaka's gold market.
It is lined with shops selling gold jewellery, and there are dozens of small alleyways leading to workshops where the jewellery is made.
According to the local trade association, there are about 350 gold shops and workshops here in all, employing about 20,000 people.
They are mostly old family businesses, and little about them seems to have changed in centuries. The gold is softened over charcoal fires or gas burners, and then fashioned into necklaces and ear-rings by men bent over low wooden desks.
Because of the rising prices, jewellery sales have dipped
"Every morning all the workshops and gold shops are swept clean," Salahuddin, the elderly gold panner, explained.
"And somehow or other bits of gold and other precious things are swept out too. That is how it all ends up in our drains."
But the record high price of gold has been more of a curse than a blessing for Tanti Bazaar.
Fewer customers are now buying gold than before, even though no Bangladeshi wedding is truly complete without gold jewellery for the bride.
People are already worse off because the price of their staple food, rice, has doubled in the past year, and fuel costs have soared.
As a result, businessmen estimate that as many as two-thirds of all workers in the market have been sacked this year.
"We've had to lay off many of our employees because the high price of jewellery is scaring off our customers," shop owner Prodip Ghosh said. "This business is just no good anymore."
This means that much less gold is now finding its way into the sewers, so Mohammed Harun and Salahuddin complain that they are earning less than last year.
The streets of Dhaka are not, after all, paved with gold.