A savvy couple have snapped up the best property deal in San Francisco, buying a gated street with 38 mansions on it for a mere $90,000.

Tina Lam and Michael Cheng now own the roads, sidewalk and other previously public areas of Presidio Terrace, a cul-de-sac that has played home to Nancy Pelosi, among other notable figures.

That's come as a shock to the residents of the street - where homes cost an average of $5.1 million - who lost the property when the governing board failed to pay a $14-a-year property tax, SF Chronicle reported.

Road to success: Tina Lam and Michael Cheng (both pictured) bought SF's Presidio Terrace for just $90,100 in 2015 after it was put up for city auction due to $991 in unpaid county taxes

Snapped up: The cul-de-sac's asphalt, sidewalk and manicured lawns now belong to the couple. Residents only found out this May when they were asked if they wanted to buy it back

The Presidio Terrace neighborhood in San Francisco is seen above in this snap taken today

Presidio Terrace, the most prestigious street in the city, was for sale because of a mere $994 in back-taxes, fines and interest

Lam, who was born in Taiwan, and Cheng, originally from Hong Kong, came across the deal in April 2015 when looking for property bargains in San Francisco, where the median home value is now $1.2 million, according to Zillow

They discovered that the private street had been put up for a city auction because its property homeowners' association hadn't paid the annual $14 county property tax in 30 years

Lam, who was born in Taiwan, and Cheng, originally from Hong Kong, came across the deal in April 2015 when looking for property bargains in San Francisco, where the median home value is now $1.2 million, according to Zillow.

They discovered that the private street had been put up for a city auction because its property homeowners' association hadn't paid the annual $14 county property tax in 30 years.

Presidio Terrace, the most prestigious street in the city, was for sale because of a mere $994 in back-taxes, fines and interest.

The couple - who live in San Jose, 45 miles away from San Francisco - put their winning $90,100 bid down without even checking out the property first.

Over the past two years the residents of the gated street have gone about their business, unaware that the asphalt, sidewalks, manicured islands, plants and palm trees surrounding them were now owned by the couple.

The map above shows where the neighborhood is located in San Francisco

Ironically, sales of houses on the street were restricted to whites only until 1948.

In the intervening two years, Lam and Cheng have been looking at ways to monetize their newly acquired plot.

'We were looking to get title insurance so it could be marketable,' Cheng said.

But eventually they decided that they could charge 'a reasonable rent' for the 120 parking spaces on the street instead.

Driven crazy: Lam and Cheng are now planning to charge for parking on the road, which is upsetting residents. The homeowners are now trying to get control of the street back

Pricey: Homes on the street cost an average of $5.1m. The homeowner's association didn't pay the taxes because the bills had been sent to an accountant they hadn't used since the 1980s

And if Presidio Terrace's occupants weren't interested, then perhaps others from outside the gated community would snap up the deal instead.

The locals only found out that they'd lost their land on May 30, when they were contacted to see if they were interested in buying it back.

They learned that the reason the homeowner's association hadn't paid the bills was that the city's notices had been going to an accountant who hadn't been employed by the street since the 1980s.

They were not pleased.

'I was shocked to learn this could happen, and am deeply troubled that anyone would choose to take advantage of the situation and buy our street and sidewalks,' one homeowner, who did not wish to be named, told the Chronicle.

Famous face: House minority leader Nancy Pelosi (seen with husband Paul in February) is one notable former resident of the street

Others complained that the city did not notify them of the auction.

But city spokeswoman Amanda Fried was unapologetic.

'Ninety-nine percent of property owners in San Francisco know what they need to do, and they pay their taxes on time,' she said.

'And they keep their mailing address up to date.'

She added that her office can do 'nothing' about the sale now.

However, the homeowners' association is still trying to have the results of the auction overturned.

That may not be an easy matter, however, because the sale went through two years ago.

In the meantime, they have filed a suit against the city and the couple to try to stop the street being sold while other litigation about the auction is pending.

As well as Pelosi, other notable former residents of the street include San Francisco Mayor Joseph Alioto, and Senator Dianne Feinstein and her husband, financier Richard C Blum.