Hang Toi, more commonly known as Dark Cave, has been tweaked to appeal to adventure seekers.
The six kilometre Dark Cave is located within Phong Nha-Ke Bang National Park. The main entrance is on Ho Chi Minh Highway West, about five kilometres north of Paradise Cave. Unlike Paradise Cave, which is artificially lit and is about politely observing the interior from a fenced boardwalk, Dark Cave is about plunging in. It has been developed into a playground, as evidenced by the 400-metre zip-line to the entrance of the cave.
Once inside the cave, you will have to switch your head-torch on as you walk barefoot through a crevasse that gets narrower & muddier until it is walls of thick clay to each side and underfoot. Eventually there is no trail, just deep footprints left from the person in front. Every step (and misstep) becomes a comical struggle of squelching for 300 metres.
Finally the crevasse widens into one big mud pit.
The mud is remarkable. It’s consistency and colour are one you will remember. As well as this it’s incredibly buoyant. You’ll be able to effortlessly float, bob up and down and roll around and around.
On returning to the mouth of the cave you can swim in the cave’s crisp, cold river in pitch darkness.
Head back up stream in kayaks, then be entertained once more with an obstacle course over the water and a flying fox.