When Leon Krier described his reaction upon seeing Nevada City for the first time last week, his eyes lit up and a smile swept across his face.

Not a big deal, really, considering that is the reaction most people have when they discover the quaint 154-year-old town. But considering Krier's title as the intellectual godfather of an architectural school of thought dubbed Traditional Urbanism, that smile says a lot.

"I knew the town very well from a novel by Louis Lamour," Krier said in his Euro-tinged accent. "I'm amazed at how clear he was."

With his swirling gray hair, wire-rimmed glasses, scarf and Kissingeresque intonations, the 57-year-old native of Luxembourg - who lived in London for 20 years and currently lives in southern France - appears every bit the intellectual. That appearance should counter entirely the picture of Krier thumbing through western paperbacks. But because of a mischievous streak that lurks below his academician's exterior, it doesn't.

Adherents of Traditional or New Urbanism - essentially the idea of the traditional city where community life is within walking distance of homes - call Krier the godfather of that planning concept. His role is more akin to a polemicist stirring up the pot of architectural thought.

Krier designed the master plan for Poundbury, a new town commissioned in the late 1980s by Prince Charles that is modeled on a traditional English village.

He also worked on Alessandria, a new town in Italy designed in a classical style.

So Leon Krier - the architect who rubs elbows with royalty, who has created new-old communities, taught architecture and town planning at the Royal College of Arts in London, Princeton and Yale, and is known for his advocacy of traditional architecture - is an aficionado of the Wild West.

For Krier, the streets, the buildings and the feel of Nevada City and Grass Valley are the epitome of the traditional western city on a par with the best of Europe.

And that, he said, should be a lesson for the four special development areas in Grass Valley that could add some 3,000 homes to the county within 20 years.

"It is so remarkable in an area that has grown so much in 50 years, that the significant parts are the ones that were built over 100 years ago," Krier said.

"It speaks to the structural wealth of the patterns on which they were built."

Through his theories, writings and designs, such as master planning Seaside, Fla., considered the model for traditional communities in the United States, 80 acres of land is roughly the ideal size for developing contemporary communities - or a quarter of a city - using the New Urbanism concept. The best planning for such a development would include jobs, shopping and amenities within a quarter-mile radius, allowing residents to comfortably walk to their destinations rather than drive.

"The suburban way of development is the most wasteful," Krier said. "It is fragmented. It doesn't really fit together.

"Town planning is more to do with networking. Modern planning is almost the exact opposite."

And planning was why Krier was visiting Northern California. Before arriving in Nevada County, he was in Chico consulting on the proposed Doe Park community.

In Grass Valley, he was a guest of Phil Carville, who is heading up the Loma Rica development for the Getty Trust.

Current plans for Loma Rica call for, among other things, a mixture of 1,000 housing types built in clustered, pedestrian-oriented villages.

Of the 452 acres that make up Loma Rica Ranch, Carville said 125 acres will be developed. The balance will be recreation and open space.

"This property can set the bar for development not only in Grass Valley, but in the state," Carville said. "We bought the property to prevent a disaster."

After consulting on Loma Rica for two days, Krier said he liked what he saw.

"I think Loma Rica will be absolutely perfect," he said.