Thẩm Mã Pass

Thẩm Mã Pass sits on Highway 4C between Yên Minh and Đồng Văn on the Hà Giang Loop, one of the route's signature stops thanks to its nine dramatic switchback bends (giving it the alternate name Dốc Chín Khoanh, 'Nine-Coil Slope'). The pass crests above a wide valley of terraced fields hemmed in by limestone karst, with the Đồng Văn plateau opening up ahead - one of the moments on the loop where the landscape shifts from forested mountain to open rocky plateau.

The name Thẩm Mã has a specific historical origin: it was traditionally the slope where pack horses carrying goods were tested for strength, with those that reached the top still strong kept as working animals, while weaker ones met a different fate at highland markets. A second, more romantic legend attached to the same pass holds that couples who cross it hand in hand are destined to stay together for life.

It's about 112km from Hà Giang city, roughly 3 hours by motorbike via Quản Bạ and Yên Minh. Precisely because it's this scenic and this storied, Thẩm Mã has become one of the most popular photo stops on the entire loop, often photographed from the famous 'Z-bend' viewpoint where the full run of switchbacks - sometimes likened to a ribbon of silk draped across the mountainside - comes into view, with H'Mông village rooftops visible in the valley below.

That popularity means it's also one of the more crowded stops on the route, particularly during the Sep-Nov buckwheat flower season and on weekends, when traffic here has made local news for extended jams.

Thẩm Mã Pass is on Highway 4C, on the stretch of the Loop road between Yên Minh and Đồng Văn (via Phố Cáo). Riders doing the standard loop clockwise from Hà Giang city pass through it on day 2 or 3, after Quản Bạ and Yên Minh. There's no reason to make a special trip - it's a natural part of the route.

Be aware that this stretch can see significant traffic during peak season weekends, so build in extra time if you're travelling then.

The pass has a small viewpoint area at the top where riders typically stop for photos, along with roadside stalls selling drinks and snacks, and often local children with handmade flower garlands for sale. The view takes in terraced valleys dropping away to the south and the rocky karst plateau stretching north toward Đồng Văn.

The road itself is well-surfaced with manageable corners, though loose gravel can appear on some bends. During quieter periods (weekdays, off-peak season) the atmosphere is genuinely peaceful; during peak buckwheat season weekends, expect a busy, sometimes congested scene with many other travellers stopped for the same photos.

Don't rush through Thẩm Mã in the race to reach Đồng Văn - the views here are genuinely worth 20 minutes, provided you time it to avoid the worst crowds. Given its fame, this is a place where an early morning or weekday visit makes a real difference to the experience; arriving on a Saturday afternoon during buckwheat season risks getting caught in the kind of traffic jam that has made local news.

It's also worth going in with eyes open about the pass's growing pains: as more informal vendors and photo-prop services have set up along the roadside, some longtime visitors feel the spot has lost some of its original, unmediated character, and there are real local conversations about how to balance tourism income with safety, sustainable management, and the community's own connection to the land. None of that erases the pass's genuine visual drama, but it's part of an honest picture of what you'll find there today.

If you're doing the loop over 3 days, Thẩm Mã typically falls on day 2 between Yên Minh and Đồng Văn overnight.