In Hanoi, soup is a way of life — the connective tissue of Vietnamese culture. With noodles and herbs, it strings together twisting streets and varied lifestyles. Here the bones, crumpled napkins and squeezed limes that litter the ground beneath tiny plastic tables are symbols of a good meal and a life well lived.

Hanoi has a growing reputation as a culinary capital. And pho — rice noodles in savory broth with a variety of meat and herbs — is Vietnam's national dish. Bun cha — a combination of grilled pork, sweet and savory broth with fish sauce, sliced green papaya, rice noodles and fresh herbs — is the signature dish of Hanoi. Besides these belly-warming staples, you can satisfy your appetite with all manner of noodle soups for breakfast, lunch and dinner.

The abundance of options makes looking for the perfect bowl of noodles in Hanoi a tricky one. It's a quest that will lead you through the city's back alleys, grand French-influenced boulevards and tucked-away neighborhoods. In searching for sustenance, you'll find religion, history, art and the theater of everyday life as it plays out on the motor scooter-packed streets.

I decided to stick to the city's ubiquitous street stalls, and I vowed to eat whatever was set before me, no matter how mysterious. Although I dumped an entire bowl of soup in an alley when the old woman who served me wasn't looking because I thought I spotted an animal's eyeball staring up at me from the broth.

A bowl of soup on the street in Hanoi usually sells for 15,000 to 25,000 Vietnamese dong — 72 cents to about $1.20 — so eating this way here is a steal. By contrast, a bowl of simple and comparatively bland pho ga (chicken pho) or pho bo (beef pho) at the elegant French colonial Hotel Metropole goes for about $12.50.

Follow the elders

To help me gauge which street stalls were superior, I enlisted the help of Mai Thi Thu Trang, a young woman who manages the Arriba Mexican Restaurant & Grill, one of Hanoi's few (and maybe only) Mexican restaurants. Trang gave me a bit of advice that guided my quest.

"Places that are good are normally places that old people come to eat," Trang said. "Because they believe in the quality."

Early the next morning, she took me to a stall that she said served some of the best breakfast noodles in the city. It was deep in the Old Quarter, a collection of 36 tightly knit streets that retain the layout and much of the architecture of early 20th century Hanoi, with roots stretching as far back as the 11th century when the city was established.

Historically, each street in the Old Quarter attracted and was named for a type of artisan or merchant, such as silk traders, jewelry makers or blacksmiths, and many of the streets retain these clusters, although commercialism and a thriving tourist trade now define much of the quaint area. Still, strolling the Old Quarter is one of the great joys of Hanoi.

I was particularly taken with the warrenlike streets surrounding the Dong Xuan Market, where I ducked into stalls to gawk at buckets of writhing fish, chicken claws and exotic herbs and spices. I bought a puffed sesame baguette and munched on it as I roamed, ending in the cold quiet of the Bach Ma temple, said to be the oldest place of worship in Hanoi.

Trang led me through the chaos of these streets, turning off Hang Buom into tiny Ta Hien Street. There she pointed out a small shop (No. 2C) where a wizened old woman in traditional dress sat eating on the high stoop (a good sign). She beckoned me to sit on a knee-high plastic blue stool at a similarly doll-sized table. A younger woman sat on another stool above two steaming pots.

One pot was filled with broth into which she put noodles plucked from inside a glass case that held bowls of brown eggs, salt and chopped green onions, and plates of pig's feet, sliced pork and raw meatballs. I didn't order; she just made a bowl of noodles, broth, a dash of salt, a sprinkling of herbs, pickled garlic, meatballs and slices of soft pork and handed it to me.

The dish, called bun doc mung, was a revelation: The broth was rich and fragrant, the meatballs light and redolent of spices. The soup sustained me well past lunch as I wandered south to Hoan Kiem Lake and stopped at Ngoc Son temple, which is on a little island.

Food and history

With a renewed sense of Zen, I headed to the French Quarter, where the air suddenly felt cooler, thanks to the many trees that shaded the wide boulevards flanked by stately villas and mansions, legacies of an earlier era when Hanoi was the capital of French Indochina.

I ate my second-favorite bowl of soup at a stall marked No. 9 in an alley called Ngo Trang Tien, across from the Hanoi Opera House. Called bun dau, it was a lovely, light noodle soup with a tomato-based broth, dry red chili paste, crunchy greens and tender little pillows of fried tofu that exploded with curd when I bit into them.

That evening, back in the Old Quarter, I decided to take a chance. At the busy corner of Hang Bo and Hang Can, I happened on a bustling stall where teenagers waited in line to eat fried chicken feet, dipped in salt and lime juice, and a noodle-based soup in a blood-black broth in which small pieces of chicken and liver floated.

The soup went well with a bottle of lukewarm 333 beer, but it didn't rival the bowl of noodles I'd eaten that morning on Ta Hien Street, where the wise old woman had beckoned to me with the promise of the glorious day to come.