What is Nui Da Bia (Stone Inscription Mountain) in Phu Yen?
Nui Da Bia is a 706m peak west of Tuy Hoa near the Khanh Hoa border. On the summit: a giant granite boulder — visible from Highway 1 — inscribed by 14th-century Cham king Che Man marking his kingdom's southern boundary. The hike is 3–4 hours return with no guide needed. Almost no foreign tourists.
From the window of a northbound train between Nha Trang and Tuy Hoa, a granite finger pokes above the tree line on the western side of the valley. That’s Nui Da Bia — the Stone Inscription Mountain — and most passengers have no idea what they’re looking at.
The boulder at the summit is roughly 15 meters tall, standing at the peak of a 706-meter mountain in what was once the borderland between two kingdoms. In the 14th century, the Cham king Che Man had text carved into its face marking the southern limit of Champa territory. The inscription is still there.
Location and access
Nui Da Bia is in Song Hinh district, in the hill country west of Tuy Hoa near the Khanh Hoa provincial boundary. From Tuy Hoa city, take National Highway 29 west — the mountain becomes visible after about 30 kilometers. The trailhead is in Son Long commune; look for signs and motorbike parking. Total driving time from Tuy Hoa: approximately 45 minutes.
The hike
The trail to the summit is approximately 3–4 kilometers one way, gaining about 500 meters of elevation. Time: 1.5 to 2 hours up, slightly less down. Total round trip: 3 to 4 hours.
The trail is clear and well-worn in the lower section — locals use it regularly. Higher up it narrows and the footing becomes less reliable: loose stone, exposed roots, steep sections. Proper footwear is necessary. The summit is open ground around the boulder, with 360-degree views of the surrounding mountain terrain and the coastal plain to the east.
Best conditions: Early dry season (January to March). Cool, clear, and the trail is firm. Avoid the September to November rainy season — the trail becomes slippery and muddy, and there’s occasional flash flooding in the lower gullies.
Start time: Before 7am. The summit is fully exposed and heats up quickly after 9am in the dry season.
The inscription
King Che Man (Jayasimhavarman III) ruled Champa from approximately 1307 to 1312 AD. His territorial arrangements with the Vietnamese Tran dynasty — trading the northern Cham provinces of O and Ly in exchange for a royal bride — were among the most consequential acts in the history of Vietnamese southward expansion. The Nui Da Bia inscription is one of his territorial markers.
The characters are carved into the face of the boulder in Cham script, now partially eroded. The inscription’s content has been interpreted by scholars as a boundary claim — this mountain as the southern limit of Champa’s effective control.
What to bring
- Water (at least 2 liters per person)
- Food — nothing available at the trailhead or on the trail
- Sun protection — the summit has no shade
- Hiking footwear — not sandals or flip-flops
- Headlamp if starting very early