Red Stone Mountain rises directly above Langmusi and is the most accessible hike in the area, achievable in about an hour and a half round trip from the village. The sandstone formations at the summit are a deep ochre-red against the blue sky common at this altitude, and the prayer flags accumulated there over years of monastic attention make a striking visual combination. The panoramic view from the summit takes in the entire Langmusi valley and, on clear days, the snow peaks to the south that mark the higher country of northern Sichuan.
The trail begins from the village and is well-worn. The altitude — the summit is around 3,700 metres — makes the final approach steeper than it looks and slower than expected for those not acclimatised. Start in the morning before weather builds; thunderstorms are common in the afternoons during summer months and the exposed summit ridge is not a safe place to be caught in lightning. The descent to the village on the far side, following a different path, adds variety if you have the time.