King Mongkut Memorial Park of Science and Technology at Wa Ko

The King Mongkut Memorial Park at Waghor marks one of the most significant spots in Thai scientific history: the Gulf-coast beach in Prachuap Khiri Khan where King Mongkut (Rama IV) watched the total solar eclipse he had predicted, on 18 August 1868. Today it’s an educational science park with interactive exhibits and a large aquarium. Entry is modest (around 50 THB for adults), and it’s open Tuesday to Sunday.

The history

Two years ahead, King Mongkut calculated that a total eclipse would be visible from the remote village of Waghor, and in 1868 he brought scientists and foreign diplomats to a camp built there to observe it. The prediction was precise — the achievement that earned him the title “Father of Science and Technology in Siam,” and why 18 August is now Thailand’s National Science Day. The expedition had a tragic coda: both the king and the young Prince Chulalongkorn caught malaria, and Mongkut died six weeks later. King Bhumibol dedicated the memorial park here in 1990.

What to see

The park pairs that story with hands-on science: interactive physics and technology exhibits, an astronomy and planetarium section nodding to the king’s own instruments, and outdoor nature displays. The big family draw is the Waghor Aquarium — one of Thailand’s larger public aquariums, with walk-through tanks of Gulf and reef marine life. It’s firmly an educational day out, well suited to children and often busy with school groups.

Insider Tip: Come in the cooler morning hours, and treat the aquarium as the centrepiece with kids in tow — it’s the part most visitors rate highest, and it gives the historical exhibits more context once you’ve seen the sea life the king’s coast supports.

Practical notes

It’s at Khlong Wan, just south of Prachuap town on the coast — easiest by car. Entry is around 50 THB for adults and 30 for children; it’s generally open Tuesday to Sunday, roughly 09:00 to 16:00, though check ahead as the aquarium can keep separate hours.

Watch out: It’s a science-and-aquarium park, not a beach attraction — set expectations for an educational visit. Some exhibits are Thai-language first, so families with older kids get the most from it.

The park is at Khlong Wan, Mueang Prachuap Khiri Khan District, Prachuap Khiri Khan 77000. View on Google Maps.