Reed Flute Cave in 3D: Guilin’s Lit Limestone Chamber

A limestone cave under a hill in Guilin, hollowed out by water, hung with stalactites and lit in deliberate colour, with a pool at the bottom that reflects the whole chamber. Here is how to explore Reed Flute Cave and the karst above it in 3D from your iPhone.

Reed Flute Cave runs about 240 metres into a hill on the northwestern edge of Guilin, in Guangxi, southern China. It is a limestone cave of the ordinary kind — stalactites, stalagmites, columns and curtains, all built by water carrying dissolved calcium carbonate and leaving it behind drop by drop — and it is presented in a way that is not ordinary at all, lit throughout in saturated colour.

The name comes from the reeds that grow at the entrance, which were traditionally cut and made into flutes. Inside, on the walls, there are ink inscriptions left by visitors more than a thousand years ago, during the Tang dynasty, which is a useful reminder that this was a destination long before it had lighting rigs.

You can explore Guilin and the hill above the cave today, in full 3D with live Street View, right from your phone.

What makes Reed Flute Cave special

The largest chamber is known as the Crystal Palace of the Dragon King, and it is where the cave earns its reputation. A shallow, absolutely still pool covers part of the floor, and with the formations lit from below and behind, the reflection doubles the chamber so completely that it is genuinely difficult to tell where the rock ends and the water begins.

The lighting divides opinion, and it is worth being straight about it. Purists find it garish and would rather see the stone under white light. The counter-argument is that colour separates formations that would otherwise read as a single grey mass to a visitor walking through in twenty minutes. Either way, the underlying cave is real and the shapes are not enhanced — only lit.

What is above ground matters as much. Guilin sits in the most famous tower karst landscape on Earth: hundreds of steep, isolated limestone hills rising abruptly from flat ground, the shape that Chinese landscape painting has been working with for centuries. The cave and the towers are the same process seen from inside and out.

How to explore Guilin in 3D

This is where MAPAS comes in. The inside of the cave is a walking tour, but the karst around it is exactly what 3D terrain was made for.

For a first run, try this order:

1. Search for Guilin, China and switch to 3D so the towers separate from the flat ground between them.
2. Tilt low and fly between the hills at the height of the rooftops to see how abrupt the sides are — these are cliffs, not slopes.
3. Find Guangming Hill on the northwestern edge of the city, the hill the Reed Flute Cave runs into.
4. Move southeast to Elephant Trunk Hill, where the Li River has cut an arch through the base of a tower.
5. Follow the Li River downstream toward Yangshuo, where the towers get denser and the valley narrower.
6. Drop into Street View along the riverbank and in the old streets of Yangshuo to get the scale from the ground.

Beyond the cave

• Elephant Trunk Hill — a karst tower on the riverbank with a natural arch that looks like an elephant drinking.
• Fubo Hill — a tower rising straight out of the Li River in the city, with steps to a viewpoint over the rooftops.
• Seven Star Park — a large park east of the river with its own cave system and several towers inside it.
• The Li River to Yangshuo — the classic 80-kilometre stretch, the landscape printed on the back of the twenty-yuan note.
• Longji rice terraces — two hours north, a completely different landform carved into the mountainsides by hand.

Why Guilin looks like that

Seen flat, Guilin is a city with some hills in it. Seen in 3D, it is unmistakably a landscape built by dissolution rather than uplift.

This region was a shallow tropical sea for a very long time, and the limestone laid down then is thick, pure and heavily jointed. Warm, wet, mildly acidic rainfall attacks that limestone along its joints, widening them into gullies and then into gaps. Over millions of years the gaps win: what is left standing are the blocks that happened to be least fractured, and they end up isolated, steep-sided and roughly cylindrical.

The caves are the same process underground. Water sinking through the rock hollows out passages and chambers, and once the water table drops those chambers drain and begin filling with the formations that visitors come to see. Reed Flute Cave is a hollow inside one of the towers. Tilt the terrain, look at how the hills stand apart on a flat floodplain, and the relationship between the two is immediate.

Before you go

Reed Flute Cave sits a short taxi ride from central Guilin and is open daily, with tickets sold at the entrance. It gets busy, particularly with tour groups in the middle of the day; early morning is calmer.

Guilin’s weather is subtropical — hot and humid in summer with heavy rain, cool and often misty in winter. The mist is not a problem for the landscape; it is arguably what makes it. Spring and autumn are the comfortable months. Inside the cave the temperature is steady and cool year-round, which is a relief in August and less so in January.

Common questions

How long does the cave tour take?

Around forty minutes to an hour, walked as a one-way loop with lighting cues along the route. It is not a strenuous walk, but the path is wet and has steps.

Is the colour lighting artificial?

Yes. The formations are natural; the coloured lighting is installed and deliberate. Nothing has been painted or added to the rock itself.

Is MAPAS free to use?

Yes. It is free on the App Store, needs no sign-up before you start exploring, and works on iPhone and iPad.

No queue, no tour group, no twenty minutes to take it all in. Just a hollow hill in the middle of the most famous karst landscape in the world, laid out in three dimensions with the towers around it.

Open MAPAS and fly the Guilin karst from the Reed Flute hill down the Li River.