BEIJING — For China's capital, one slogan best sums up the Summer Games: "New Olympics, New Beijing."

In its bid to prepare for the Games, which begin Friday, China has transformed the metropolis by razing large sections of older, traditional neighborhoods and investing billions of dollars in many of the world's most ambitious architecture projects.

Besides 31 new and renovated venues for the Olympics — including the iconic National Stadium, a structure dubbed the Bird's Nest because of its unique design of interlocking steel girders, and the National Aquatics Center, a translucent block often called the Water Cube — the government and state-owned companies have constructed dozens of futuristic and superlative buildings.

The National Opera House, designed by French architect Paul Andreu and nicknamed the Duck Egg, is a $440 million ovoid plated with titanium sheets and set in a reflecting pool near the ancient Forbidden City, the one-time ceremonial and political center of Chinese government.

Part of a new 755-foot-tall headquarters for the China Central Television Corp. seems to defy gravity by hanging over empty space.

Those four buildings highlight a much grander renovation of the 3,000-year-old city. Beijing spent some $42 billion to beautify the city and prepare for the Games. It added new parks, roads, hotels, subway lines and the world's largest airport terminal, a 1.8-mile-long building.

For city residents — both Chinese and foreigners — the changes have been nothing short of transformative, for better and worse.

Some citizens have welcomed the changes. Du Dong, a Chinese architect who lived in Los Angeles and South Bend, Ind., before moving to Beijing in 2001, said Beijing was among the world's most interesting cities for architects.

"Beijing is like a showcase for China with a lot of buildings designed by foreign architects ... so there are a lot of different styles," he said. "Everyone wants to show off."

Olav Kristoffer Bauer, a 24-year-old Atlanta native who runs six restaurants in Beijing, said he liked how the city had "used the Olympics as a catalyst to improve."

Unlike a major American city, which "is all divided into suburbs," Beijing's dense population of 17 million people makes it lively throughout, he said.

"It just has a gut feeling," Bauer said. "The people are cool and it's fast paced without being too fast paced."

Other residents, however, worry that Beijing has lost much of its character during its radical makeover.

Michael Meyer, a Minnesotan who moved to Beijing in 1997 and wrote The Last Days of Old Beijing, a chronicle of living in one of the city's oldest neighborhoods, said that only "a fraction" of the city's traditional narrow streets remain, with many having been destroyed in recent years.

As the older neighborhoods have been replaced with more modern buildings, Beijing's "irreplaceable, intangible cultural heritage" has been eroded, he said.

Andreas Karras, the chief executive officer of Karras Architects Inc., said Beijing had paid too much for its new iconic buildings.

The National Stadium is "an impressive structure, but at what cost?" he said.

Besides Beijing's Imperial-era buildings — the Forbidden City, the Great Wall and the remaining neighborhoods of courtyard homes — these are some of the structures certain to turn heads during the Beijing Games:

Beijing National Stadium: Also called the Bird's Nest, the $500 million National Stadium will seat 91,000 people for the opening and closing ceremonies, athletics and soccer. It at the southern end of the 1.2-mile-long Olympic Park, the nexus of the Summer Olympics with venues, parks, corporate exhibition halls and press centers.

The National Aquatics Center: Covered with blue plastic bubbles, the Water Cube, as it is often called, will host swimming and diving events. It sits next to the National Stadium and has a seating capacity of 17,000.

The Beijing National Indoor Stadium: This futuristic structure can seat 19,000 people and will host artistic gymnastics, trampoline and handball competitions.

The Beijing Shooting Range: This new hall in western Beijing, not far from a mountain retreat once used by Chinese emperors, will host 10 shooting events during the Olympics. The building was designed in the shape of a hunting bow, the origin of modern shooting. It can seat 8,600 people.

Wukesong Indoor Stadium: The site of all of the Olympic basketball matches, the new building is part of a development including three baseball fields. It will accommodate 18,000 visitors.

The Shunyi Olympic Rowing and Canoeing Park: A large outdoor area that will host rowing, kayaking, canoeing and marathon swimming, it will hold up to 27,000 people during the Games.

The National Theater: Designed by French architect Paul Andreu, this building has divided Beijing. Some people love its reflective titanium sheath and pool. Others consider it horribly out of place beside the Forbidden City. Either way, it gets tongues wagging.

The China Central Television Corporation Headquarters: This unusual structure — a giant M-shape with its center suspended in midair — had upset some Chinese for its $1.1 billion cost. Other people argue that its distinctive design by Dutch architect Rem Koolhaas is the kind of eye candy that will keep tourists flocking to Beijing for years.

Beijing International Airport Terminal Three: The world's largest airport terminal, this 1.8-mile-long building designed by British architect Norman Foster has earned praise for its open, airy interior and convenient transportation but has suffered some of the baggage handling problems that have plagued London's Heathrow Airport. Some travelers avoid checking in baggage.