A hand-drawn map of Bangkok shows us what we’re missing out on with digital maps

Navigating the streets of Bangkok can challenge even the most seasoned of travelers. Roads wind into each other instead of running parallel. Narrow alleyways loop into dead-ends. The hodgepodge routinely stumps Google Maps and GPS devices, and even the main waterway, the Chao Phraya River, weaves through the city like a child’s messy squiggle as opposed to a clean, sharp line.

Savvy visitors simply ditch those digital devices in favor of a much simpler navigational aid: The hand-held paper maps of American artist Nancy Chandler, whose colorful descriptions of Bangkok have gained a cult-like following since they launched nearly four decades ago.

Chandler produced the first map in 1974 as in inset in Sawaddi, a magazine produced by the local American Women’s Club. “It was more like a group of women going to the market and taking notes,” recalled Chandler, now 74, of the initial project. But when the organization commissioned a second printing of the now-defunct magazine for “people who kept calling for the magazine with the map,” she said, members of the group insisted that she had a viable business on her hands.

The maps have been updated ever since, with the oldest of Nancy’s three daughters, Nima Chandler, acting as chief of research for the past 14 years. The business, called Nancy Chandler Graphics, also now offers maps of the smaller neighborhood of Old Bangkok, the northern city of Chiang Mai, and later this year, the Vietnamese capital of Hanoi, and has expanded to sell greeting cards, wrapping paper, mugs, and coloring books that portray aspects of Thai culture as well.

The maps have remained popular in part because they offer a lot more than just a way to get from one place to another. They also offer carefully curated recommendations. Rather than depicting a traditional city layout, or firing off a laundry list of attractions in the style of a guidebook, Chandler’s maps combine the best of both worlds, plotting destinations while adding pithy advice or useful tips about what to expect. The expertise come from meticulous research and well-placed connections. “If we stopped selling maps,” said Nancy Chandler, “we could become taxi drivers.”

Mother and daughter also offer contrasting approaches to what makes the cut. Nancy Chandler remains nostalgic for classic sites like the Chao Praya River “just for the fresh air,” and Chinatown, a neighborhood that she says has changed very little, “because I love old buildings.”

Nima Chandler, in contrast, is excited by newer, trendier places like the Bangkok Tree House, a rare eco-friendly hotel that also houses an organic restaurant, and Mr. Jones’ Orphanage Milk Bar, a high-concept dessert joint recently opened by Ashley Sutton, an Australian entrepreneur who has launched several other successful eateries around town.

Here are a few of the mapmaking Chandlers’ tips on how visitors to Bangkok can make sense of the city:

—Thais love nicknames. One of the city’s main thoroughfares, Sukhumvit Road, originates in Bangkok and extends over 250 miles (400 kilometers) into the countryside. The Bangkok-based portion, popular for its street vendors, restaurants and nightlife, is intersected by dozens of sois, or streets, that are evenly numbered along one side and oddly numbered along the other. But the even-and-odd pairs don’t always run parallel: soi 53, for example, becomes soi 36 once it passes through Sukhumvit. As the map notes, “when travelling to this area, refer to sois by their nicknames” if they exist. Any mention of Thong Lo (soi 55) or Ekkamai (soi 63) will be instantly recognized by locals and taxi drivers. Likewise, locals refer to Chinatown as Yaowarat, the name of the street that runs through it.

—Get a phone number for your destination and know what’s nearby. For example, it might be easier for your taxi driver to find the Little Home Bakery, a culinary mainstay since 1951, if you say that it’s a block from Wat Sakhet, a well-known temple. Getting directions over the phone might also be preferable to whipping out your GPS. Taxi drivers often hail from poorer regions and might be newcomers themselves, and while “Thais learn provincial maps in school,” they mainly study political boundaries but not necessarily city layouts, according to Nima Chandler.

—Opening hours can be unpredictable. Popular destinations might be open earlier or later than expected, or be closed on random days of the week. Don’t grab lunch at Asiatique, a newly-opened waterfront shopping complex — it’s only open from 5 p.m. until midnight. Chatuchak Weekend Market, a gigantic open-air bazaar and one of the city’s most popular attractions, is open from 9 a.m. to 6 p.m. on Saturdays and Sundays, but hosts a flower market on Wednesdays and Thursdays from 5 a.m. to 6 p.m. The flower market at Pak Khlong is a 24/7 affair, but is best during the wee hours of the morning when vendors receive new produce.

—Beware of name changes. According to Nima Chandler, newly-opened restaurants sometimes shutter or change names within a matter of weeks, which is why the Chandler women update their site — http://www.nancychandler.net — about once a month. Do what the mapmakers do: If in doubt, call ahead to confirm.

—Look beyond the brochures. Near the backpacker haven of Khao San Road, Wat Bowonniwet is well-known as the Buddhist temple where the country’s beloved monarch, King Bhumibol Adulyadej, served his monkhood. Lesser-known facts are that he designed the onsite water wheel, and that the temple houses the country’s only library of ancient funeral books, tomes that document the lives of the dead. So keep an eye out — a site’s most memorable quirks might not be advertised.

—Not everything goes in Bangkok. Sleeves are required for all Buddhist temples, while flip-flops are banned from most night clubs. As the map points out, smoking is banned on the outdoor grounds of Chatuchak Market: “Step outside the market if you must, or risk at 2,000 baht fine.” That $65 is better spent on a souvenir, lavish meal or any number of unforgettable experiences in the Venice of the East.