Belum Caves

The first thing you notice is the air. Step down from the bright, dry plateau and the heat changes character. It becomes heavy and damp, and it settles on your skin like a warm cloth. Somewhere ahead, water drips onto stone. The light above you narrows to a pale circle, and then the earth closes over your head.

You are entering the Belum Caves, in the Kurnool district of Andhra Pradesh, in southern India. This is one of the longest cave systems on the Indian subcontinent that ordinary visitors can walk through. The surveyed passages run for more than three kilometres under the farmland. Only part of that is open to the public, but the open section is enough to make your sense of direction feel unreliable.

Look back at the entrance before you go deeper. The caves do not open from a cliff face, as many people expect. Instead, they open from the ground, through sinkhole-like shafts that drop down from the flat surface. For centuries, people in the nearby villages knew these holes in the earth. The name Belum is often linked to an old Sanskrit word for a hole or a cave, which is a plain description of what visitors saw.

The rock around you is limestone. Over a very long period of time, water moved slowly through cracks in this stone. Geologists connect the caves with underground water from the Chitravati River system, which runs through this region. Limestone dissolves slowly in slightly acidic water. Drop by drop, the water carved hollow halls, narrow tunnels, and the strange hanging shapes you will see as you walk.

Those shapes are stalactites and stalagmites. Here is an easy way to remember the difference. Stalactites hang tight to the ceiling. Stalagmites grow up from the ground. Each one forms as mineral-rich water drips, evaporates, and leaves a thin film of calcite behind. These formations grow extremely slowly. So when you see a column joining floor and ceiling, you are looking at a very long process that is now complete.

Now, a small surprise. The caves were well known to local people, but serious scientific attention came late. A British geologist, Robert Bruce Foote, recorded the caves in the late nineteenth century. Then, nearly a century later, in the early 1980s, a German expedition led by the caver Herbert Daniel Gebauer mapped the passages in detail. Their survey work helped to show how large the system really is.

The second surprise is about the people who sat here long before the surveyors. Archaeologists have found traces of Buddhist and Jain monks in the caves. Pottery and other remains from the Buddhist period have been recovered, and some of these finds are kept in a museum in the nearby town of Anantapur. It is easy to imagine why monks chose this place. Down here, the noise of the world above disappears.

That quiet is the reason for one chamber with a gentle name: the Dhyana Mandir, which means the meditation hall. Pause here if the path allows it. Listen. You will hear footsteps, voices from other visitors, and the steady hum of the ventilation system. But between those sounds there is a deep stillness. Few places in a busy country offer this kind of silence.

Further along, you may reach a chamber called Kotilingalu. In the Hindu tradition, the lingam is a rounded stone form that represents the god Shiva. Here, many stalactites hang and rise in similar rounded shapes, and local people named the chamber after them. The name means something like a countless number of lingams. It shows how the caves became part of local religious imagination as well as local geography.

Another chamber carries the name Saptasvarala Guha, the chamber of seven notes. Some of the rock formations here produce musical tones when they are tapped, because thin sheets of calcite can ring like a bell. Please do not test this yourself. Touching the formations leaves oils from your skin on the stone, and those oils can stop new growth. The caves are fragile, even when they look solid and permanent.

The lowest point open to visitors is called Patalaganga. In Hindu stories, Patala is the underworld, and Ganga is the sacred river. Here, a small stream of water flows and then disappears into the rock. It is a modest sight, but think about where you are standing. You are now far below the fields, and this water continues its slow work of shaping the caves.

The passages you have walked through were not always this easy to explore. The state tourism authorities developed the caves for visitors in the early 2000s. They added lighting, paved walkways, and ventilation shafts, which bring fresh air into chambers that were once stuffy and hard to breathe in. Notice how the coloured lights change the stone. Under one lamp the limestone looks gold. Under another it looks pale grey.

When you return to the surface, take a moment before you leave. Near the entrance, a large statue of the Buddha sits facing the landscape. It is a modern addition, a reminder of the monks who once used these caves. Around it, the countryside is flat and quiet, with fields, scrub, and a wide sky. Nothing on the surface tells you about the halls below your feet.

So stand still for a moment. Feel the dry heat again after the damp air underground. Notice how bright the daylight looks to your eyes. Somewhere beneath this ground, water is still dripping in the dark, and a stalactite is still growing by a tiny amount. You have walked through a place that took an extraordinarily long time to make, and it is still being made now.