The Wind Cave Nature Reserve is part of the Bau Formation, a narrow belt of limestone covering about 150 sq km of Southwest Sarawak. Due to the comparatively soft and soluble nature of limestone, and the intense tropical rainfall of the region, the whole of the Bau Formation is intersected with caves. Whilst many caves of the Bau Formation are remote and inaccessible, the Wind Cave is within easy reach of Kuching and is a popular day trip and picnic destination. The Wind Cave Nature Reserve covers 6.16 hectares and includes the cave itself and the surrounding forest.

The Wind Cave is believed to have got its name from the cooling breeze blowing continuously through the cave. It a smooth, tubular limestone cave formed during the Jurrassic-Cretaceous period, roughly 60 million years ago. Excavations by early explorers such as Beccari in 1865 have shown that the Wind Cave was inhabited until recent times. Earthenware vessels, charcoal and pieces of marine and freshwater shells were found. The deep pits within the cave may have been made by gold prospectors in the 1930's.

A 1000-metre plankwalk runs throughout the length of the cave, so it is easy and safe to explore, although the interior of the cave is unlit and therefore a flashlight is essential. A small stream meanders through the cave and joins the Sungai Sarawak Kanan at the northern end. The main cave passages are wide with flat roofs, while the smaller passages form an irregular network in the northern section of the cave.

The Wind Cave’s main features include stalagmites, stalactites, and pillars which form when these two join together. Other features include conical cavities separated by blade-like pinnacles of limestone, limestone pendants hanging from the roof of the cave passage, and current scallops which have a honeycomb appearance and indicate the direction of the water flow.

Throughout the length of the cave, the high-pitched squeaking of thousands of bats can be heard, including a number of insect-eating species, as well as a large population of Dusky Fruit Bats. There are also thousands of Black Nest Swiftlets nesting in the cave, and their nests, made almost entirely from the swiftlets’ glutinous saliva, can be seen adhering to the nooks and crannies of the upper cave wall.

At the end of the cave passage, the plankwalk emerges onto the hillside and a path leads down to the bank of the Sungai Sarawak Kanan, one of the two major tributaries of the Sarawak River. There is a narrow sandy beach along the river bank, with public changing rooms, so this is the perfect place to swim and cool off after visiting the cave. There is also a picnic area and some stalls selling snacks and drinks.