With all due respect to the $495 silver bracelet in Tiffany's window, what I like best about downtown Walnut Creek's newest batch of shops is the 200-year-old oak tree out back.

As for the 14-screen multiplex that opened last summer, the truly memorable plot twist is how 50-foot-high glass walls make a theater lobby seem like a display case.

The fact that these projects opened last year within a block of each other speaks volumes about why Walnut Creek has the East Bay's healthiest downtown. They're reminders that good cities find smart ways to grow -- and growth should never be predictable. Sometimes the key is to hold firm to the past. At other times you need to confound expectations.

And if you can do both, all the better.

That's what happened at Mount Diablo Boulevard and Main Street, the intersection that forms a hinge between Walnut Creek's traditional downtown, with its mostly independent shops and restaurants, and the brand names housed in the low-slung stucco of Broadway Plaza and its spawn. This is the Walnut Creek that attracts outsiders, a retail zone keyed to the same sprawling affluence that has created gold-plated shopping centers in places like Corte Madera and Palo Alto so that big spenders don't need to drive to Union Square for a splurge.

At first glance, the complex known as the Corners fits squarely into the latter category. The centerpiece is jeweler Tiffany & Co., two stories high with marble-lined columns. The other tenants? Eye-roll, please: a Tommy Bahama so Mom and Dad can look sharp at the next barbecue, an Apple Computer store for the home office and Pottery Barn Kids so the tykes can teethe in style.

But there's also a wine bar called Va de Vi doing brisk business despite the head-scratching name and a penchant for double-digit reds. Business should get even better once the dining terrace opens in the handsome rear courtyard, which wraps around a venerable oak.

And therein lies a tale.

A bank building once filled half the site, leaving plenty of room for the oak to survey the latest changes around it. But when Lamorinda Development bought the site in 2000, the grand vision of Tiffany et al came with a supposed need for 70 parking spaces.

Lamorinda proposed lining the two streets with storefronts, folding a garage in back and consigning the oak to oblivion. Lamorinda also offered the city $105,000 to spend on mature oaks that it could plant somewhere else.

Here's the punch line: The city balked. "The tree needs to stay," said then-City Manager Don Blubaugh, a sentiment rightly echoed by local politicians. "It represents values of this community" -- such as the desire to preserve tangible evidence of the days when Walnut Creek was a place with orchards in every direction and packing sheds downtown.

The project found other parking spaces. Tiffany's stayed on board. And the tree went from being an obstacle to a design centerpiece.

"The oak makes our project unique," says developer Brian Hirahara, of Lamorinda, who has moved his office from Orinda to a second-floor space with windows on the courtyard. "We want people to be back there."

Cynics put off by Walnut Creek's success might dismiss the Corners as elaborate mimicry, a costume drama of consumerism, and to some extent they're right. But the scale works, and the details radiate care. For instance, you reach the oak via a cobblestone path with one-story brick-covered buildings on each side that keep their neighbor from seeming cramped.

They know their place.

The Century Theatres 14-plex at Olympic Boulevard and Locust Street is a bolder, simpler tale.

The starting point is obvious. From Petaluma to Hayward, Redwood City to Pleasant Hill, suburban downtowns are getting their very own movie palaces as in the Good Old Days (albeit with a dozen or more additional screens). Too bad they're designed with all the imagination of a "Lethal Weapon" sequel: neon and wavy Art Deco lines to evoke the aforementioned G.O.D. -- end of story.

The approach by architect Hans Baldauf and developer Blake Hunt Ventures breaks the mold. Instead of emulating the past, they've created a hard-edged box of light that is the most contemporary thing downtown.

The glass walls encase a grand three-story lobby that's a riot of rich colors and action. They form a corner that's framed by -- surprise! -- zebra-striped concrete blocks and topped by a flat steel roof braced by round steel columns painted white.

By day, the cinema makes a nice contrast to the stucco all around. At night -- whomp.

"We wanted something dramatic that would open up and energize the corner, " says Baldauf, a partner at BCV Architects in San Francisco, which also designed the Corners.

The use of bare concrete blocks was inspired by both aesthetics and economics: "It was a way to maximize resources," Baldauf explains. "We figured if we used the concrete block to good effect, instead of spending money to cover it with stucco, we could pump all our effort into the lobby."

Neither project is perfect. The concrete blocks don't offer a crisp enough contrast of black and white, for instance: They're dark gray and light gray, a bit muddy. And the Corners, though elegant, is more about setting a familiar mood than making a fresh statement.

But here's what counts: This is first-rate urbanism that strengthens what's around it. The projects expand Walnut Creek's pedestrian downtown -- always a plus -- and deliver predictable goods in unexpected ways.

And they didn't happen by chance. In the case of Tiffany, the city placed a higher value on a local oak than a retail legend -- and got both. With the multiplex, which anchors a retail complex called Olympic Place, the city drew up a plan in 1997 spelling out what it wanted on the site. It then waited for a developer willing to play by those rules.

"Walnut Creek has been incredibly exemplary in the vision picture," Baldauf says. "It has known how it wanted to evolve and how to push developers to up the ante in quality."

Consider: This downtown has shrugged off threats from shopping malls and big-box retailers. Growth has brought precious boutiques, but also two supermarkets and a new public park geared to downtown residents.

Less obviously, the new projects serve as a safety valve by reducing gentrification pressure on older tenants and buildings. Maybe that's why Tiki Tom's can peddle $6 mai-tais on Olympic Boulevard next to the new Ruth's Chris Steak House with its $69.95 porterhouse for two.

So let the cynics sneer. Walnut Creek has found a way to plan for the future that allows room for the things that residents want -- including a glimpse of a fine old tree that predates us all.