Hat Hin Lak Si, situated within Mu Ko Phetra National Park at Khao To Ngai in Satun Province, is recognized as one of Thailand's most significant geological learning sites. Its primary scientific distinction, which attracts global attention, is the clearly visible "Geological Contact" between two distinct eras. While geological boundaries spanning millions of years are typically obscured by environmental changes or buried deep underground, this site features a prominent exposure along the seaside cliffs, easily accessible via the walkway popularly known as the "Time Traveller Bridge."

In technical terms, this location exhibits the contact between the Tarutao Group and the Thung Song Group. The Tarutao Group consists of reddish-brown sandstone from the Cambrian Period (approximately 541–485 million years ago), while the Thung Song Group comprises grey limestone from the Ordovician Period (approximately 485–443 million years ago). This phenomenon is caused by a "Normal Fault," a tectonic shift that brought these two geological successions—separated by tens of millions of years—into direct contact. The diverse colors of the stones are not merely aesthetic; they serve as a planetary record documenting the transition of ancient environments from shallow marine siliciclastic deposits to carbonate platforms.

The surrounding landscape features a kilometer-long wooden and concrete bridge that winds along the western cliffs of Khao To Ngai. This path offers visitors an immersive experience through a well-preserved coastal forest, accompanied by the therapeutic sound of waves hitting the rocks. Furthermore, it serves as a spectacular viewpoint for the Andaman Sea, offering clear vistas of various islands within the national park. As a testament to its global significance, this site is a key component of the Satun UNESCO Global Geopark—Thailand’s first-ever Global Geopark—honored for its unique geological heritage and its commitment to sustainable eco-tourism management.

• From Satun city center, take Highway 406 and 416 toward La-ngu District. Turn left onto Highway 4052 toward Pak Bara Pier. The national park entrance is located approximately 1-2 kilometers before reaching the pier.

• Visit in the early morning or late afternoon to avoid heat and enjoy the best lighting for photography

• Come during low tide to clearly see the multi-colored rock formations and explore more easily

• Wear proper footwear suitable for walking on rocky surfaces to prevent slipping or injuries

• Bring drinking water and sun protection, as the area can be hot with limited shade

Admission Fees:

• Thai Citizens: Adults 20 THB, Children 10 THB

• Foreigners: Adults 200 THB, Children 100 THB

Opening Hours:

• Open 24 hours a day, every day.