Every Friday, a dusty valley half an hour outside Oaxaca City fills with thousands of people and a whole lot of cattle. El Baratillo de San Antonino Castillo Velasco is the largest open-air livestock market in southern Mexico, and according to travel magazine Roads & Kingdoms, it deserves the spotlight all on its own.

The market spreads across a flat plain dotted with mesquite trees and cacti, drawing more than 3,000 buyers, ranchers, and traders every week — plus, as the magazine puts it, a great many cows. It's the heart of the region's deep cowboy culture, a world most visitors to Oaxaca never see because they stick to the city's mezcal bars and mole kitchens.

Roads & Kingdoms singled it out as the first entry in its new "One Great Thing" series — a format reserved for places the magazine considers so singular they can't be squeezed into a standard city guide. The recommendation came from the publication's annual autumn trip to Oaxaca, hosted alongside local expert Ana Paulina Garcia, whose knowledge of the state's food and traditions anchors these journeys.

What makes El Baratillo worth the detour is its authenticity. This isn't a market staged for tourists; it's a working livestock exchange where rural Oaxacans buy and sell cattle, haggle, and catch up on the week's news. For travellers, it's a rare window into the ranching traditions that shape much of the state's food culture — the birria, the barbacoa, the grilled meats that define Oaxacan eating often start in places exactly like this.

Getting there is easy. The market sits in San Antonino Castillo Velasco, roughly 30 minutes from Oaxaca City by car or colectivo taxi, and it only happens on Fridays — so plan your week in the city around it. Go early, wear shoes you don't mind getting dusty, and be prepared for a sensory overload of animal sounds, street food stalls, and fast-paced Zapotec- and Spanish-language haggling.

A couple of practical notes: this is a working market, not a photo set, so ask before pointing a camera at people or their animals, and bring cash in small bills if you want to eat or drink at the stalls. Combine a Friday morning here with a mezcal palenque visit in the surrounding Valles Centrales and you'll have one of the most complete day trips Oaxaca State can offer.

For anyone who thinks Oaxaca is only about food tours and textiles, El Baratillo is the reminder that the state's cultural depth runs well beyond the city limits — straight into cowboy country.