Now a wall conceals a little cove of entrepreneurship where several migrant families sell socks, book bags, pants, noodles and shish kebabs cooked in a spicy soup. One family behind the wall sells ice cream, popsicles and cold drinks from a refrigerator on wheels.  Zhao Fengxia, a neighbor who owns three shops, said she believed that officials and developers were using Olympic beautification as a pretext to strangle their business and put pressure on them to leave. Feng Pan, 18, who helps her parents run a noodle shop, accepted the official view less critically. “We influence the city’s appearance,” she said.  A planning official, Zhi Wenguang, said, “We extended an existing wall to improve the overall environment for Olympic events.”  Many cities have sought to remake their image when hosting global events like the Olympics. Beijing is polishing off one of the world’s most expensive makeovers with a whitewash. Along the historic central axis of the city that runs from the Yongdingmen Gate due north to the Drum Tower, the authorities are doing their best to give the old city a new face. Beijing has spent $130 million to restore buildings, many of them temples along the five-mile axis, according to the city’s cultural relics bureau.  The Olympic Stadium was built on a northern extension of the traditional axis — a nod to the event’s historic importance. On the wide boulevards leading up to the stadium, roadblocks have been set up and flowers, grass and trees planted.  The southern part of the axis has proved more difficult to beautify. It cuts through densely populated neighborhoods south of Tiananmen Square that are home to many of the city’s migrants and working poor. To hide neighborhoods leveled for redevelopment in recent years or anything else the government considers unsightly, officials have put up walls.  Mr. Song and his wife and 8-year-old daughter now live behind one. They have lived here since 1994, Mr. Song said, renting out his shops to families from the provinces.  They live in close quarters. The Songs’ room is barely big enough for a double bed on which the couple and daughter sleep. Two pet birds live in metal cages by the door. The birds, brown starlings with dark feathers and orange beaks, can parrot human speech. Mr. Song taught the birds one of the most famous poems of the Tang Dynasty. Every few minutes, it squawks lines from the poem: “The white sun falls over the mountains” or “The Yellow River flows into the sea.”  Behind the room is a moonscape of weeds and rubble that used to be a slum. Mr. Song’s place survived while the city razed the poor Tianqiao neighborhood and transformed it with shopping malls, wider streets and subdivisions. Mr. Song’s predicament is familiar in the churn of this changing city. The developers want him to go, but he is holding out for more money.  On July 17, several workers left a pile of red bricks on the sidewalk. The next morning, they returned, wearing sandals and straw hats, accompanied by the police and local officials. They set to work laying brick at 8:30 a.m.  The wall did not go up easily. After a brief shoving match, a little demonstration unfolded. Mr. Song hung three Chinese flags from the trunks of trees — and three white flags emblazoned with the 2008 Olympic logo. A migrant worker climbed a ladder and stuck up a poster that said, “Need Human Rights!!!”  To scare away the officials, Mr. Song brought out a large poster with a famous photograph of Mao sitting in a wicker chair. “He thought Mao might be able to do something for us,” joked Ms. Zhao, the neighbor, who was there that morning.  The bricklayers worked through a hard rain. As a crowd of sympathetic morning commuters gathered, the police strung up a police tape around the poplar trees. A dozen men in slacks and polo shirts stood around, keeping the situation under control.  “One person shouted, ‘So you’re not going to allow people to feed themselves!’ ” Ms. Zhao recalled. “A lot of families earn their livelihoods from these shops — even though they’re small.”  Gu Dahua, 47, a farmer from Anhui Province, came here with his wife three years ago. They sell combs, mirrors, socks and other small commodities all priced at 1 yuan, or about 15 cents. The wall has not been good for business.  “It’s hard now,” Mr. Gu said.  Two blocks north, another store along the axis has been closed for the Games.  Sun Ruonan’s ancestors opened a bakery on the axis south of Tiananmen Square in the 1840s. The city tried to tear down the building last year to plant grass and ornamental shrubs beside the Olympic marathon route. Ms. Sun and her younger sister, Ruoyu, an Australian citizen, refused to vacate.  Last Tuesday, Ms. Sun, 57, sat alone in the dining room of the restaurant, surrounded by her cats. Festive paper lanterns hung in the dining room, which smelled of cat litter and decay. It was 4 p.m., and Ms. Sun was still in her pajamas.  “I don’t really want to oppose the government,” she said, breaking into tears. “For those of us who have lived through the Cultural Revolution, this life is like heaven.”  The city has bullied her to leave. One night last year, a bulldozer slammed into the building. Neighbors are paid to keep watch over her, and they notify the police when she has guests. Ms. Sun said officials pressed her doctor into refusing to give her care.  Her building is falling apart. The government, for the sake of appearances, has put up scaffolding with green netting around it. As the runners pass her home in August, it will be easy for spectators to miss the posters, begging for help, taped to the door.  “I’m hanging here like a nail,” she said.  A version of this article appears in print on , on Page A1 of the New York edition with the headline: Before Guests, Beijing Hides Some Messes. Order Reprints| Today's Paper|Subscribe
Some businesses and residents will spend the Olympics behind walls erected to keep their property out of sight.