A few hundred feet farther north, your jaw will drop at The Grotto, 40-foot-high faux bois, or "false wood," concrete creation, with river water tumbling through it, created by San Antonio artist Carlos Cortes.

Among the barge stops is one for the oldest VFW post in Texas, housed in a 19th-century mansion, which has a bar and outdoor seating open to the public. Another is at the San Antonio Museum of Art, housed in the century-old former Lone Star Brewery. The museum has built a new shaded pavilion and terrace backing to the river.

The last stop is at another local landmark, the former Pearl Brewery, which is being redeveloped into a multi-use shopping and residential complex. Among the tenants already are a farmer's market and a branch of the Culinary Institute of America.

The River Walk is an asset that makes cities worldwide envious - because none of them have been able to duplicate it or match its appeal to visitors and locals alike. Enthusiasm for the extension has been running high here for months and reached a crescendo three weeks ago when Mayor Phil Hardberger and other leaders pushed a button to start the operation of the lock and the opening of the Museum Reach.

Thousands of people, most of them San Antonio residents like Benny Bellamy and his wife, Lou, waited patiently in line for more than an hour to take one of the free barge rides on the Museum Reach that were available on the first weekend.

"I like this," Bellamy said after disembarking from the boat ride. "We don't just wait until visitors come to town. We love to go to the river any time. We've lived here 28 years, and it's a good place to be."

The opening coincided with the last days of Hardberger's four years in office. He is a former judge who once lived on the river, had his law office there, and has bought burial plots for himself and his wife, Linda, in a South San Antonio cemetery on it.

Hardberger had wanted to see the River Walk extended since he tried canoeing from his home to his office, on what is now the Museum Reach, decades ago. He found the river an overgrown, trash-filled ditch. After years of planning by his predecessors, Hardberger is widely credited with pushing the City Council after taking office in 2005 to complete the Museum Reach, as a way to both sustain tourism and provide a unique amenity for residents.

Hardberger waxes poetic about the river at every opportunity, describing it as San Antonio's beating heart since the city's founding three centuries ago.

"It's the reason there is a San Antonio," he said in an interview. "It was always a green spot in hard country, a place surrounded by lots of cactus and rattlesnakes and not much else."

"We know people were here 10,000 years ago," he said during the opening ceremony. "We've been here 300 years. The river has bound us together. It is the major artery of this city. It is the most beautiful part. The river is timeless . . . and eternal."

If You Go

Getting there

Southwest Airlines has the only nonstop flights between Philadelphia and San Antonio International Airport. Connecting service is available on AirTran, American, Continental, Delta, Northwest, and United. Southwest's nonstop fare is $232 for travel later this summer; connecting flights on other airlines are slightly more.

Places to stay

San Antonio has 12,000 downtown hotel rooms, with every chain represented. The better the view of the original portion of the River Walk, the more expensive rooms generally are.

San Antonio Marriott River Walk, 889 E. Market St., 1-800-648-4462.

Omni La Mansion del Rio, 112 College St., 1-800-292-7300.

Holiday Inn El Tropicano, three blocks south of the new Museum Reach, 110 Lexington Ave., 877- 863-4780.

Crockett Hotel, next to the Alamo, 320 Bonham St., 1-800-292-1050.