For the first time in my life, I defied the odds and overcame my fears by going caving. You know, entering dark passages with twisty tunnels that are hollow homes to hairy, stealthy arachnids. Empty passages that echo heartbeats distinctly when the last of the bats shriek their way out at dusk.

Dank. Sometimes foul thanks to guano or bat poo. Claustrophobic. But mostly, pitch black. You crack silly jokes with the guides because the sound of your own voice is comforting.

Which is why, if you've never been in a cave for more than ten minutes (and I'm not referring to showcase caves that have built in lightings and platforms), you've never quite lived in full at all. For some, like me, it is a life changing experience as you conquer your phobias, overcome self-induced scary imaginations and test your max for bravado.

The best place to go caving (if you live in Southeast Asia) is Sarawak, East Malaysia, and if you can't spare the time exploring beyond the capital city of Kuching, despair not. Kuching is the best place to combine a city holiday with an underground adventure, and can be done within a weekend. Depending on your physical capability, previous caving experience and gung-ho attitude, you can opt for beginner, intermediate or advance level of this ecologically-sound activity that puts safety first.

In Kuching alone according to caving specialist James Handfield-Jones, there are 300 caves (when he last counted). "We discovered eight new ones last weekend through a local chap who was bathing in the river." British-born James who runs Kuching Caving adventure tours company informs me that the caves are often secrets which are well guarded by the Bidayuh ethnic group, whose home this has been for many generations. The caves, high in the limestone karst (towering limestone mountains) were defensive frontiers during tribal wars such as the historical bloody warfare between the Bidayuhs and Ibans.

Switlets love hiding within calcite formations.

Gunung Nambi at Kampong Bantang, the one I explored, has 15 cave entrances with about 3km of known passages. We entered the Gua Sireh ("Gua" is cave in Malay) in the side of the mountain where the rights to which are owned by families from the village. The head of one of these families is a very jolly Bidayuh called Frankie who doubled as a guide. "When I was young, I used to climb on these bamboo poles to collect nests of the cave swiftlets," he said, pointing to thick poles left on the cave ground.

A kilogram of swiftlet nest would fetch precious dollars, right up to RM7,000 or around USD2,000, enough for tribes to depend on this resource for income. Swiftlet nests are believed by the Chinese to have healing properties. It is used, for instance, in bird's nest soups, with the prime ingredient being the bird's spit that glues the nest together.

"Now we do not have that many nests anymore; we realize that the more we took, the fewer swiftlets there were," he said, acknowledging that communities realise that dabbling with nature through the bird nest trade has its consequences.

Apart from learning about the delicate balance of nature and the role each animal has to play in nature's Disneyland called ecosystem, there's lots to see and discover about the amazing geological formations of caves.

James holding a sea shell found in a cave.

In Kuching caves for instance, you'll learn that caves formed by mildly acidic water dissolving the rock when it is under the water table are part of phreatic formation. With vadose formation, however, openings are created by erosion of rivers and that this occurs above the water table.

Magnificent water erosion marks can be seen on rocks to show that where you stand was all once under water. I found smatterings of fossil marine shells at the entrance of the caves around 50 feet up sea level. How could that have happened? "Looking at the Borneo inland sea, I would think that the whole of Sarawak was once submerged under water," said James.

Indeed, limestone deposition in the Kuching area can be traced back to 150 million years ago at the bottom of the sea. "Complex geological processes folded the limestone and the sandstone with which it is interspersed. Magma intruded into the fractures and subsequent erosion and uplift created both the landscape we see today and the caves inside the mountains," explained James.

No wonder in Kuching, I am informed, some hills are volcanic while others are wholly made of limestone. The longest cave system found stretches for 6km and the largest chamber has a floor area of about 32,000 square metres.

Forget the circus; take your kids to caves. They will be thrilled in spotting spiders that flash green eyes against torchlight, also bats, swiftlets and if lucky, a slithery snake. "The snakes are more afraid of you than you are of them," laughed James during the pre-caving brief. He was right, and I was thankful for the early warning. One beautiful green reptile snaked away from me as I tried approaching it - it was a beautiful experience.

Charcoal cave drawings on festivals and funerals.

Kids will wonder at the fact that once upon a time people lived in caves, cooked and raised families in the dark chambers too. Just like keeping diaries, they drew on the walls. Amazing and ancient charcoal drawings can still be seen today in a few Kuching caves, with distinct images of centuries-old tribes, ceremonies, garbs, fish, fowl and beasts. Each tells a story, trapped in the past.

"Gua Sireh in Gunung Nambi has produced evidence of the earliest human occupation in the Kuching area around 20,000 years ago," he said, adding that there are also proofs of the earliest rice cultivation in Asia there.

With caving, as in any other nature-bound activity, it is imperative that we minimize our human impact on natural habitats. For instance, keeping voices low and not shining the torchlight directly into the eyes of the creatures as that tends to blind them (that's why flash photography is not allowed in the dark areas of caves). With increased human activities, animals tend to relocate to another habitat as a means of self-preservation, hence disrupting their natural equilibrium, so it's good to be sparse.

Kuching Caving limits the use of caves to maintain ecological integrity and emphasises "take nothing out, leave nothing behind" policy. James, conserving the environment added, "We also do our bit to improve the cave environment by organising cleanups to remove accumulated rubbish and graffiti."

Communities get to be part of this burgeoning ecotourism industry as well. "We seek the approval of the local community from whom we hire our local guides and to whom we pay a levy for every paying guest," explained James. Another way of stimulating income is to encourage the local community to provide homestays, cultural entertainment and dishing out creative cuisines that honour age-old traditions.

Guests on a two-day expedition can stay in the local community and bask in Bidayuh heritage, listening to the owner's countryside yarns. Three accommodation options are available including longhouses and an upmarket farmhouse. The third is to live in Kampung Rais Sibran, one of the last remaining hill villages. Whichever accommodation is selected, with Kuching Caving, there's always time for a chat on archaeology, geology and the biology of the caves.

Really, the adventure is there for you to seize. As for me, at the end of my cave exploration, I emerged from the gloom drenched with my own sweat, thirsty like hell but with the brightest gleam in my eyes that would light up the darkest cave.