Wat Umong is one of the most unusual temples in Chiang Mai — built around a network of dark brick tunnels that burrow beneath a large forested stupa mound on the western edge of the city. The tunnels date to the 14th century and still contain ancient Buddha images and niches. Walking through them, your eyes adjust gradually to the dimness before emerging at the other end into bright forest.
Beyond the tunnels, the monastery grounds are expansive and genuinely peaceful — a working Buddhist community with monks, novices, and meditation retreatants. A large pond, forest paths, and philosophical sayings written on boards hung from trees give the place a contemplative quality. The stupa mound is covered in trees that have grown over the brick for centuries.