A life’s journey through cave systems

MY fascination with caves emanates from a young age when exploring sea caves, at low tide, excavated by wave action in the granite cliffs of West Cornwall, England. Many of these caves were used by smugglers and ship wreckers for storing contraband French wine and brandy and valuables in the 17th and 18th centuries.

Near the entrance of these caves, seagulls swirled around overhead and dived down to their face cliff nests. It was not until later while studying Geomorphology as part of my degree at Oxford that my interest in subterranean caverns in limestone landscapes evolved under the tutorship of Dr Marjorie Sweeting, who later was one of the leaders of an international expedition in 1997 to 1978 to explore Sarawak’s Mulu Caves.

Most subterranean caves are found in permeable massive limestone or karst scenery where water charged with carbonic acid (H2CO3) runs through vertical joints and horizontal bedding planes, dissolving and widening these natural passageways.

The largest caverns in Europe, North America, and Northern China were created by the vast floodwaters of the melting ice-sheets at the end of the Pleistocene glaciations about 11,000 years ago.

Yet, other cave systems may be found in Chalk rocks, as seen in England’s North Downs in Kent County. These caverns have been used for the refrigerated storage of imported LPG (liquefied petroleum gas) from the nearby Canvey Island terminal.

Recently the demand for LPG has declined, thus shutting down some refrigerated areas with the subsequent collapse, through subsidence, of the housing areas built on the surface.

When head of Geography at two very large schools in the Northwest of England and later in South England, I took my senior students to the Yorkshire Dales National Park and to the Peak District National Park. Both areas are in the Pennine chain of mountains where massive carboniferous limestone scenery can be seen and we visited Gaping Ghyll, a sink hole leading down to cavernous passages underground.

In the Peak District, we went underground at Trek Cliff caverns where the valuable jewellery mineral Blue John had crystallised in the joints of the limestone passageways and had once been mined.

Today, with cave lighting, spectacular limestone features may be seen. On one expedition to these caves, after 20 minutes underground, a female student developed claustrophobia, necessitating me to take her back in pitch darkness to the entrance.

Fortunately, we both had headlights and outside, with a cup of hot tea, she calmed down.

Visits to limestone caverns in Malaysia

In 1994, former Malaysian students took me to visit the Batu Caves near Kuala Lumpur. After climbing what seemed like an endless stairway with snapping macaques perched on the handrails, I was mesmerised by the sheer size and height of this sacred cave system.

In 2001, while inspecting an international school in Kuching, I was taken by four teachers one Sunday afternoon to visit Bau caves. It was an unforgettable experience to see swiftlets close up and to see hatchlings in their nests.

Undoubtedly, the greatest experience I have ever had in cave visits was in 1998, whilst receiving a proposed millennium year expedition for senior students at my school in England, when I flew from Kota Kinabalu to Miri to visit Niah Caves.

The caves at Niah

These caves were first discovered by Robert Coulson, a British mining engineer who was working in a colliery on the Sarawak-Brunei border. He was prospecting for tin ore intruded into the joints and bedding planes in the limestone at Niah.

Alfred R Wallace stayed with Coulson for eight months and in April 1864, he wrote a paper to the Natural History Review explaining Coulson’s discovery in the caves of bones and teeth of animals and primitive humans.

In this paper, Wallace appealed for funds to support Coulson in further exploration and the gathering of samples for scientific examination. This fell on deaf ears and eventually, Alfred Everett surveyed the caves.

It would take another 90 years before then curator of Sarawak Museum Tom Harrisson and wife Barbara made significant discoveries in their excavations of Niah Caves. The assorted bones that they found were taken to various USA universities for further examination and dating.

The human bones were eventually returned to their final and rightful resting place in Sarawak 50 years later. Barbara discovered ‘The Deep Skull’ along with human bones, which were dated to be 38,000 years old.

Recent studies have concluded that the first human activity in the caves dates from 46,000 to 39,000 years ago, dating back to Palaeolithic times.

The Painted Cave reveals primitive art and boat coffins in which early man buried his dead. Very recently, the oldest cave art in the world, depicting a pig and three human beings, dating back to 51,000 years ago, was discovered on the Indonesian island of Sulawesi.

It was in 1998 that my late wife and I, together with a dear Sabahan friend, explored these caves.

Today, the Niah National Park has constructed a concrete trail for about 2km leading up to the caves’ entrance. With headlamps switched on, we trod carefully over the slimy bat and swiftlet droppings on the cave’s floor, with the waft of the pungent aroma created by the guano infiltrating our nostrils.

Until relatively recently and at certain times of the year, local people were allowed to harvest the guano and sell as garden fertiliser and collect swiftlet nests from the cave roofs.

At the time of our visit, we saw no other visitors in the big cave, yet people’s voices were heard! There were lighted tents inside the cave and the lights were extinguished and voices reduced to whispers as we approached.

The sides of the cave from ground level to the roof were wreathed in bamboo poles lashed together to create a form of scaffolding up which young men nimbly climbed to harvest birds’ nests.

Towards the back of the Great Cave, a shaft of sunlight emblazoned the pitch-dark interior. This was caused by a sinkhole on the above ground surface along which an overground stream plummeted to the depths below.

Regrettably, we did not stay until dusk to see thousands of bats exiting the caves in search of food. These caves are well worth a family visit to witness nature at its very best.

Troglodytes – cave dwellers

There are very few areas in our world where people live or have lived in caves as they are mostly occupied by animals such as hyenas, lions and bears.

Fossil remains have been found of many animals, which retreated and lived in caves during the Pleistocene glacial advance in Europe.

Today, in my garden, I have several wren families (Troglodytes troglodytes) nesting in cavities in a very old slate wall. These are the smallest birds in Britain.

The very famous Peking Man (Homo erectus pekinensis), found in the Zhoukoudian caves near Beijing, China, suggests that humans lived there 750,000 years ago.

Today, it is estimated that 30 million Chinese people live in cave dwellings mostly in the easily excavated loess plateau in Shaanxi Province. These dwellings are known as ‘yaodong’, with many reinforced with brick structures leading into several chambers with mains electricity and water supplies fully connected. Such homes are cool in summer, and warm in winter.

Temperate European caves have been used by man, because of their constant year-round temperature of 10 degrees Celsius, for the storage of wine and cheese.

At Danum Valley in Sabah, boat coffins may be seen by climbing ladders to look into the voids.

The catacombs on the island of Malta were used as burial chambers by early Christians and places of refuge during Moorish invasions. During World War 2 these caves were used as natural air raid shelters and as military strategic planning centres.

On the island of Zanzibar, the catacombs there were once used by Arab traders as prisons for slaves before their deportation.

On my next visit to Sarawak, I hope to visit Mulu Caves and see the Pinnacles in the karst landscape, but meanwhile, I shall settle for smaller cave systems at Wookey Hole in the massive limestone rocks of the Mendip Hills in Somerset, England, only 50 minutes’ drive from my house.