IMPOSING mountains, lofty limestone caves and tropical rainforests are images that come to my mind when I think about Mulu National Park in Sarawak, Malaysia.

Like many people, I am captivated by the natural wonders and rich bio-diversity of this remote area in the Miri and Limbang division, tucked away at the north-western edge of Borneo.

Listed as a Unesco World Heritage Site, Mulu boasts some of the most cavernous caves on earth. The world's largest known underground chamber, dubbed the Sarawak Chamber, can accommodate eight Boeing 747s! Mulu is also home to Clearwater Cave, Southeast Asia's longest cave; and Deer Cave, the world's biggest cave passage, which can fit a building the size of London's St Paul's Cathedral.

Check out the spectacular pinnacle rock formations at Gunung Api

Three mountains frame the area - Gunung Mulu (2,377m), Gunung Api (1,750m) and Gunung Benarat (1,585m).

Mulu is known for the pinnacle rock formations at Gunung Api, the country's highest limestone mountain. The majestic 45m pinnacles soar like towering razors piercing the sky.

I have not managed to trudge to this jagged area but I have heard from adventure-seekers that this trail is not for the faint-hearted.

There are, fortunately, other attractions that are much easier to explore in the surrounding area.

Most visitors go for the daily guided tours to the well-lit 'Show Caves'. You must be accompanied by licensed National Park guides though. Upon arrival at the park's headquarters office, register and pay an entrance fee of RM10 (S$4.30) plus guide fees.

To visit Deer and Lang caves, which are accessible via plank-walks and concrete paths, the tours leave the park office in the early afternoon.

The Deer Cave's massive chambers are home to countless birds and over three million bats. At dusk, I had the chance to witness a colony of these nocturnal creatures leaving the cave in search of their daily fill of insects.

Nearby is the smaller Lang Cave, where I marvelled at curtains of beautiful limestone formations carved by nature, before continuing my walk deeper into the cave.

Towards the underground river at the end of the cave is the Garden Of Eden, with its glowing water pools, and Adam And Eve's Showers - 30m columns of water cascading from the cave's roof to the river below.

When evening draws near, stop by the Bat Observatory to view the bats' mighty exodus spiralling up into the sky. It is quite a spectacle so get your cameras ready.

Aside from these natural wonders, one of the latest features at the park is the Canopy Skywalk - the world's longest tree-based canopy walk. It is 480m in length and suspended 30m from the ground between 15 trees.

Walking on it is one of the exhilarating experiences that only a place like Mulu can offer.