Laos can be considered a country of two dimensions. One is above the ground and another one is hidden underneath—more specifically behind the steep limestone mountains.
The cave systems discovered in Laos are accessible for visitors and are truly amazing. One of the most spectacular is the Kong Lor Cave in Khammouane Province. It is about 7 kilometres long and has caverns 90 meters high. You can ride a boat right through it as a river flows along the cave. Both the karst ceiling of the cave and its floor are gorgeous, as it is believed that the emerald glowing pool in the middle of it reflects the skin of Indra, the Hindu god.
Also, the Viengxay caves in Houaphanh Province are worth visiting because this is where Lao revolutionary forces lived during the Second Indochina War. 480 caves were used as a shelter for people and even had a school, hospital, and other amenities.
Lao caves also hide some sacred Buddhists shrines—one near Luang Prabang in Pak Ou Caves and another in Khammouane Province in Tham Pa Fa Cave. The Pak Ou Caves include an upper and lower cave, and together they are a place of worship with thousands of images of Buddha in various sizes and styles. The lower cave is well lit and gathers more visitors, while upper cave requires a ten-minute trek up a steep hill. In order to reach this place, you need to travel by boat along the Mekong river. The Tham Pa Fa Cave holds 229 images of Buddha ranging in size from 15cm to over 1m tall, as well as some ancient palm leaf manuscripts. Their origin supposedly is Khmer or Vietnamese. In order to reach the cave, it is important to be in a good physical shape, as some hiking and swimming are required.
For those who are interested in visiting such magnificent places, plan your trip for the dry season when climbing and swimming in cool underground rivers is more convenient.