อุโมงค์แสงมรกต

Phu Pha Petch Cave

Useful Information

Location:	225 Moo 1 Palm Phatthana, Manang, Satun 91130. (7.124614, 99.998167)
Open:	All year daiy 8:30-15:30. [2021]
Fee:	Adults THB 100, Children THB 50. [2021]
Classification:	Karst cave Permian limestones
Light:	Incandescent Electric Light System nevertheless bring lamp
Dimension:	L=623 m, W=150 m, VR=58 m, Ar=30,500 m².
Guided tours:	self guided, D=2 h.
Photography:
Accessibility:
Bibliography:	Alan Gray (2001): Thailand and Malaysia Reconnaissance 24 February to 9 March 2000, Axbridge Caving Club Journal, March 2001. online
Address:	Phu Pha Petch Cave, Palm Phatthana, Manang District, Satun 91130, Tel: +66-74-605-466, Tel: +66-61-226-4337, Tel: +66-7477-4505. E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then. Please check rates and details directly with the companies in question if you need more recent info.

History

1998	cave discovered by a Buddhist pilgrim named Luang Ta Plaeng.
2010	cave opened as a show cave.

Description

อุโมงค์แสงมรกต (Xumongkh̒ s̄æng mrkt, Emerald Light Tunnel) is generally known as ถ้ำภูผาเพชร (Tham Phu Pha Phet, Diamond Mountain Cave). It is located at the border of Satun and Phattalong Province, and while Google Earth shows it on the Phattalong side of the border, it seems to be actually in Satun. The show cave is well developed with trails and electric light. Due to sparkling calcite crystals on the speleothems, it is called Diamond Mountain Cave.

The cave was discovered in 1998 by a Buddhist pilgrim named Luang Ta Plaeng. It was explored by a group of archaeologists from the Office of Archaeology and 10th National Museum at Songkla. They discovered remains of prehistoric humans, including a human skull and pottery decorated with seashells.

Despite being quite spacious inside, the entrance is a narrow and low passage. There is no possibility to enter the cave otherwise, and this passage allows only one person at a time, who has to stoop or even crawl to get through. This cave is not suitable for fat people.

A highlight is the huge karstfenster which allows sunlight to enter the cave passage, The stalagmite below the opening is green from the moss and lichen growing on it, so it is called Phuphaphet Jade Stone. Obviously it is not actually jade, it is just green. But this seems to be the highlight for most of the local tourists, who came here to take photos of this natural phenomena. They are throwing money on the stone for good luck.

Another strange sight is a 30 cm high penis-shaped stalagmite, which is worshipped. People actually offer flowers and prayers to this stone dildo. We guess its considered a lingam, although this is actually a Hindu believe, and the locals are Buddhists.

The cave contains a diverse fauna, which includes spiders and frogs. For your own safety avoid to touch them, some are poisonous.

There are quite annoying statements, this was the longest cave in Thailand and the third longest in the World. That's obviously complete nonsense, this cave is not even on the list of caves longer than 10 km, which contains 645 caves and 10 from Thailand. Its quite strange where such invented superlatives come from, and obviously nobody ever checks them for accuracy. Actually the main chamber is really spacious and has an area of 30,000 m² which is currently [2023] the 37th largest cave chamber in the world and the second largest in Thailand by floor area. Actually, Liz Price published quite similar things already in 2011 in a blog post, and a full report was published after her 2000 visit in ACG Journal March 2001 and is available from the MCRA website (see Literature). But with all this nonsense they actually missed to mention the actual superlative: the is one of the biggest chambers which may be visited by normal tourists on a show cave tour, 300 m long, 100 m wide and 50 m high.

Also, it is a shame that the cave was developed with wooden trails, most show cave owners follow the guidelines of the world cave conservation organisations and avoid bringing wood into caves. It is not only subject to decomposition, becomes slippery and thus unsafe, requires poisonous paint, it also has a massive negative impact on the cave fauna. The explanation is probably that the cave was developed by the Tourism Authority of Thailand, obviously without consulting cavers. Hopefully the new GeoPark status will lead to an update of the trail.