Mystery Hill in Sukhirin is a remarkable natural optical illusion located along the main road leading to Sukhirin District. At a designated stretch of Highway 4115, drivers can stop their vehicles, shift into neutral, release the brake, and observe the car slowly move forward in what appears to be an uphill direction. The experience often surprises and excites visitors, as it seems to defy gravity.

Scientifically, this phenomenon is known as a gravity hill illusion. The surrounding landscape—such as tree lines, mountain slopes, and horizon alignment—creates a visual distortion that makes a slight downhill slope appear to be uphill. Although it is an optical illusion rather than a supernatural event, the mystery and hands-on experience have made it a popular roadside attraction and photo stop in Narathiwat.

Geographically, the area lies within the Sankalakhiri mountain range, part of the vast Hala-Bala Wildlife Sanctuary, often referred to as the “Amazon of ASEAN” due to its exceptional biodiversity. The surrounding tropical rainforest is rich in large trees, wild ferns, and rare bird species. In the early morning or after rainfall, light mist often drifts across the road, adding to the mysterious atmosphere of the site.

Beyond the illusion itself, Mystery Hill serves as a gateway to Sukhirin’s ecotourism experiences. The district is known for its mountainous scenery, traditional gold panning heritage, and scenic viewpoints with sea-of-mist panoramas. Stopping at Nern Phitsawong offers a unique blend of science, nature, and local adventure before continuing deeper into the lush forests of southern Thailand.

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How to Get There

• By Car: From Narathiwat town, take Highway 4055ผ่าน Ra-ngae District toward Sukhirin. Then continue on Highway 4115 (Ra-ngae–Sukhirin Road). The Mystery Hill section is located around kilometer 30–35, just before entering Sukhirin town. Clear roadside signs indicate the location.

• By Public Transport: Take a van from Narathiwat or Su-ngai Kolok to Sukhirin and inform the driver to stop at Nern Phitsawong. However, using a private car is recommended for safely testing the rolling effect.

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Travel Tips

• When testing the rolling effect, always check for vehicles behind you and turn on hazard lights for safety.

• Visit between 7:00–9:00 AM for cooler weather and possible mist along the mountain road.

• For a clearer demonstration, place a bottle of water on the road surface and observe the direction it rolls.

• You can continue your journey to nearby attractions such as Ban To Gold Panning Site and the To Mo Shrine replica in Sukhirin District.

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Entrance Fee:

• No entrance fee (public roadside attraction).

Opening Hours:

• Accessible 24 hours a day (daylight hours are recommended for safety).