Mark Ralston/Agence France-Presse — Getty Images

HONG KONG — The photographic genre known as ruin porn — those grim pictures of mothballed auto factories, dead power plants, vine-swallowed houses — has a new theme: Olympic venues.

The Reuters photographer David Gray looked at some of the 2008 Olympic sites in Beijing and found a surprising amount of neglect and decay after just four years. His slide show is here.

Rowing, beach volleyball and cycling facilities — built new for the ’08 Games — are now deserted, rusting, even falling apart. The baseball complex, always intended to be temporary, has been demolished, its footprint covered with leftover wreckage.

At the derelict kayaking course, Mr. Gray saw a security guard dipping his bicycle innertube in the murky water, testing for punctures.

The crown jewel of Olympic architecture in 2008, of course, was the stunning National Stadium, known as the Bird’s Nest, the site of the opening and closing ceremonies and the track and field events. The reported cost of construction: nearly $500 million.

The striking stadium, with 91,000 seats, is expensive to maintain, about $10 million a year. And it has been rarely used since the Games. As my colleague Michael Wines reported, there was a Jackie Chan concert in the year after the Olympics, plus an Italian soccer match, an opera and a musicale.

Two winters ago, a playland was set up inside called Happy Ice and Snow Season. And a guy walked a tightrope strung from the stadium’s rafters for about five hours every day for two months. (Apparently, it was some sort of record. A video is here.) The Olympic Green, adjoining the Bird’s Nest, hosted a Swamp Soccer World Cup tournament last week, a 10-day romp in the mud.

These days, though, the Bird’s Nest is mostly empty. They do give tours of the place, and for the equivalent of $20 you can ride a Segway around the track where Usain Bolt sprinted to two gold medals and two world records. (A replay of the Jamaican’s 100-meter final is here – don’t blink, you’ll miss it — and the 200 is here.)

An audio tour calls the stadium “a symbol of the rise of the Chinese nation that will follow the nation’s footsteps in its rise to glory.” Rumors persist in the capital that it will become a shopping mall. Meanwhile, panhandlers dressed as Fuwa, the Beijing Olympic mascot, cruise the plazas of the Bird’s Nest, tricking passersby into posing for pictures and then demanding payment.

For a recent piece about the Olympic venues for NPR, Louisa Lim spoke to Ai Weiwei, the acclaimed artist who consulted on the design of the Bird’s Nest. He said the building had become propagandized and not integrated into the life of the city. For that reason, he told Ms. Lim, he has refused to go inside the stadium. (His comments begin at 4:15 of the audio).

Another stunning venue from 2008 was the swimming arena, the Water Cube, scene of Michael Phelps’s astonishing run of eight gold medals. At least the Cube is still operating — as a recreational water park. With $1.5 million in annual government subsidies, it breaks even.

The Cube also has begun selling limited-edition bottles of “Water Cube wine” in conjunction with China’s most famous distiller of Moutai, the gasoline-like, sorghum-based liquor.

Overbuilding, cost overruns and the expensive maintenance of world-class but rarely used venues — the chronic Olympic “legacy” issues — have long been a financial burden for host cities.

Still, the cities keep bidding and building: As Michael wrote, “the Olympics seem to bring out profligacy in even buttoned-down governments.”

In Athens, site of the 2004 Summer Games, 21 of the 22 stadiums were reported to be unoccupied by 2009. Some even blame the Greek financial crisis, in part, on the $15 billion cost of the Games.

The poster child of ill-conceived venues is undoubtedly the main Olympic Stadium in Montreal. A report on Canadian Broadcasting said the stadium became “a familiar mix of tragedy and farce,” the brainchild of Jean Drapeau, the late mayor who was “widely portrayed here as a megalomaniac who led Montreal over a cliff.”

The mayor’s supporters said he was a visionary whose idea for a signature stadium-cum-landmark was undone by poor engineering and bad luck. They cited the Eiffel Tower, originally an eyesore for Parisians, as a precedent for the stadium’s radical design.

The stadium’s parachute-like roof was not in place when the 1976 Olympics began. Later, the supporting tower caught fire; massive chunks of concrete fell off the stadium, once during a baseball game; the Kevlar roof tore; a new Teflon roof was deployed, but collapsed.

The Big O, as the stadium was locally known, soon became the Big Owe and the Big Woe. The original estimate was $134 million. In the end, it cost $1.6 billion. The overall debt from the Games took more than 30 years to pay off — accomplished through a tobacco tax.

The BBC sports editor, David Bond, recently looked at some recent Olympic venues and their legacy issues. One excerpt from his blog post: