Hup Pa Tat: Exploring the “Jurassic” Jungle of Uthai Thani

Yes, so put like that in the intro, you're going to tell me, well a chasm isn't that "curious". But here it is anyway, due to the nature of the plants growing there and the surrounding landscape.

To go into a little more detail, Hup Pa Tat is a site located 50 km west of the city of Uthai Thani , just before reaching the mountainous region of the province. It's a funny-sounding name when pronounced with a French accent, but it has an obvious meaning in Thai.

• "Hup" can be translated as valley, or even “enclosed”, therefore enclosed valley in short, which in a broader sense, defines a big hole or crater, therefore a chasm in good French.
• "Pa" means jungle or forest.
• "Tat" would be the Thai name for Arenga Pinnata, a plant of the palm family found here in abundance.

So very pragmatically, "Hup Pa Tat" simply means what the place is: "a jungle of Arenga Pinnata in a chasm".

Welcome to Jurassic Park

To sum up, Hup Pa Tat is an ancient cave whose ceiling has collapsed, preserving the fauna and flora there from almost all external (and certainly human) disturbance for millennia.

This landslide allowed the midday sun rays to penetrate the interior of the empty space of the cavity, and thus, the possibility for plants to grow. This forms a kind of microcosm with atypical vegetation, because these particular conditions, of partial sunlight and high humidity, as well as the absolute isolation of the environment, have caused a growth of unique ferns and palm trees. If these plants were common in prehistoric times, they are currently rarer and difficult to find elsewhere. This is what gives this "secret" area, surrounded by limestone cliffs, the nickname of Thai Jurassic Park (it must also be said that they like to give this kind of nickname).

To be more precise, the geology of these mountains consists of grey dolomitic limestone, dating from the Permian period , the last period of the Paleozoic Era, spanning from 245 to 286 million years ago —well before the Jurassic period, in fact! When the ceiling collapsed, the plants that had been growing on its vault eventually regrew. The limestone had decomposed, forming a layer of fine soil that could retain much more moisture in the newly formed shaft.

A short story of Hup Pa Tat

The site was discovered by chance by a monk , Phra Khru Santithamma Kosol, from the nearby temple, Wat Thom Thong. One day in 1979 , he decided to explore the valley surrounding his temple. He didn't have to go far, as the site is less than 500 meters from the temple (there is also a concrete path between the temple and Hup Pa Tat).

Venturing along the steep cliff, he first climbed before descending into the cavity, which had been isolated until then. Indeed, at that time, the tunnel through which one accesses the interior did not yet exist, so one had to want to get there! He was surprised once in the chasm to discover this jungle, so he quickly noticed the abundance of a sugar palm, considered ancient, the famous Arenga Pinnata.

To simplify access to this find, he himself dug the rock in 1984, creating this 70 m passage through which people enter today to visit the site.

That same year, the site was placed under state protection to develop it into an ecotourism destination. It is now part of the Tham Prathun Wildlife Reserve , under the jurisdiction of the Department of National Parks. The advantage is that the site is quite well-maintained, with restrooms, a souvenir shop, a café, and food options, but as a result, there is an entrance fee, just like in a national park…

Hiking the Hup Pa Tat Trail, what to expect

Concretely, the parking lot is next to the area for eating etc. and a few meters away, next to the stairs leading to the tunnel, you will have the area serving as a reception and where you have to pay the entrance fee.

Normally, it's like a national park, so the entrance fee is 200 Baht , and that's what I paid on my first visit. However, when I returned recently during the height of the Covid pandemic, the fee was reduced to 100 Baht. So we'll see if this will continue or if it will revert to the previous price once tourism returns to normal in Thailand. I should mention that during the pandemic, I did notice a decrease in entrance fees for several sites, but I tend to think that this will unfortunately remain temporary.

Once you have your ticket, you'll be asked to take a flashlight, as the 70-meter tunnel is unlit . If you prefer not to carry one, your phone's flashlight should suffice. Then it's time to climb the few steps to the entrance of the tunnel, which only takes a few minutes. Before researching this article, I was actually convinced that the tunnel was natural, and it certainly has all the hallmarks of one. When I read that it was artificially excavated, I thought it was the entire tunnel, but in fact, it's only a very small section. Aside from a possible widening to increase the height, the part actually carved directly into the rock is only the last few meters at the back of the cavern.

Anyway, here we are inside, and the least we can say is that we are greeted by the humidity, which is felt directly, in addition to a temperature naturally milder than the burning heat of summer just on the other side of the wall. We are also very quickly surrounded by the many leaves of the famous palm tree giving its name to the site. We are in the chasm, the walls that surround us are then between 150 and 200 m high.

We set off along the path and off we go. Besides the Arenga Pinnata, we come across various species, each identified by a sign. For example, there are fig trees ( Ficus benjamina ) and banyan trees with their wide trunks. As for the local fauna, you might spot small elongated tortoises , which I was lucky enough to see (you have to be observant, they blend into the scenery so well). The second time, I was treated to the presence of a type of wild pheasant, quite talkative, I might add. Rarer, as it's only visible during the rainy season, but particularly unique, you can see pink millipedes (Desmoxytes purpurosea, also called the dragon millipede). Not the most charming of animals, but this species (which is also venomous), discovered only in 2007, is found nowhere else in the world.

At one point along the path, we realize that the chasm is actually composed of two parts, separated by what remains of the original cave. The opportunity to come across some stalagmite-tite, and even an imposing column. The other part is similar to the first, so the tour is quickly done. The path runs along the cliff for a few meters, the opportunity to raise our noses and see the height separating us from the "outside".

To return to the stairs leading to the tunnel, and therefore the exit, the path goes around to the other side of the chasm, making a complete loop of 700 m.

Khao Pla Ra Mountain

If you are in the area, I invite you to continue along the mountain because the landscape is pleasant to see. Khao Pla Ra Mountain is a network of 5 small mountains, all made of limestone, with an elevation above sea level varying from 100 to 529 m.

If you are looking for something to eat or take a break, apart from the Hup Pa Tat reception, you will find what you are looking for here. In recent years, several homestays, cafes and restaurants have come to settle in the area to make the most of the place.

Both times I stopped at Ban Chai Khao – Thai-Switzerland, which is also a mango orchard, in addition to being able to cook you a little something, although in my case, it was only to enjoy the view with the platform they have set up (which is free to access). I notice the difference in atmosphere due to coming in a different season (November on the left, March on the right).

To eat, I tried to stop at the Bike Camp. The choice is very limited, so it's suitable for a snack, a little hunger or failing that, coffee and dessert. But the setting is nice, well laid out at the foot of the cliff.

Otherwise, before arriving at Hup Pa Tat, as I mentioned above, you can make a short stop at the temple thanks to which the area developed, Wat Tham Thong. Here too, the change of season gives a really different effect. In March, the 2nd time, we could see the trees in bloom on the side of the road (as everywhere in the country), which is a beautiful effect.

November on the left, March on the right.

After the temple itself has little interest, but on the cliff side, you can see a cavity with a large reclining Buddha and other statues of the sage.