A rock-cut temple was carved downwards and has no joints anywhere in it

Building by removal is the opposite of building by stacking

A conventional building is assembled. Blocks are cut elsewhere, brought to a site and set one on another, and if the mason makes an error a block can be lifted out and replaced. A rock-cut monument is made the other way round: the material is already there, and the work consists entirely of taking away everything that is not the building.

This means there is no margin for correction anywhere in the process. Stone removed cannot be put back, a miscut column cannot be swapped, and a wall that has gone too thin stays too thin. Every measurement had to be right the first time, in a medium where the workers couldn’t see most of the finished form while they were making it.

It also means the entire structure is one continuous piece of the hillside. The pillars are not supporting the ceiling in the ordinary sense; they were left standing when the surrounding rock was cut away, and the ceiling was never resting on anything because it was never separate from the mass above it.

Cutting had to start at the ceiling

The sequence is the part that surprises people most. Excavation begins at the top of the intended interior and works downwards, because that way the workers always stand on rock that has not yet been removed and never need scaffolding inside the chamber they are making.

A ceiling was therefore finished — carved, smoothed, sometimes decorated — while the floor beneath it was still solid stone many metres thick. The crew then cut down through that mass, finishing each level as they dropped, until they reached the intended floor.

The most extreme demonstration of the method is the great monolithic temple at Ellora, where the excavation went down from the top of a hillside and left an entire multi-storeyed temple standing free in the pit that the removal created. It has courtyards, towers and elephants around its base, and none of it was ever carried there.

The rock chose the possibilities

Basalt, which forms much of the northwestern Deccan, is hard, uniform and comes in thick flows without many joints, so it takes deep undercutting and large spans. The great cave groups of Maharashtra are where they are because that rock is where it is.

Softer sandstone allows faster work and finer detail but weathers much more quickly once exposed, which is why some early excavations are legible only in their sheltered parts. Granite, the material of the southern plateau, resists the chisel so stubbornly that rock-cut work in it tends towards shallow relief and smaller shrines.

The coastal site at Mamallapuram in Tamil Nadu shows the granite version of the idea: shrines carved out of standing boulders, an enormous narrative relief cut on an exposed rock face, and several pieces left visibly unfinished, which is itself instructive about how the work proceeded.

Three religions used the same technique for centuries

The tradition begins with Buddhist excavation, and the vocabulary comes from it: the chaitya, a hall with an apsidal end and a stupa in it, and the vihara, a residential hall with monks’ cells cut into the walls around a central space. Both forms imitate timber construction closely, right down to carved ribs on ceilings that are copying rafters no cave ever needed.

Hindu and Jain excavation followed, and at Ellora the three traditions sit along the same escarpment, which makes it one of the few places where a visitor can walk the shift in religious patronage rather than read about it.

The paintings at Ajanta are the other reason these sites matter, and they are also the most fragile thing in them. Pigment on a prepared surface inside a cave survives only because the cave has been dark, stable and undisturbed, and every visitor changes the humidity of the room they are standing in.

What this means for a visit

Light is the whole experience. Many of these interiors were designed for a doorway and a lamp, and the deeper chambers are genuinely dark, so a visit at midday when the sun is high can be less rewarding than one when low light reaches further in. Torches are often restricted, and where lighting is provided it is usually deliberately dim.

Photography rules at protected monuments vary by site and by which part of it you are standing in, and flash in particular is commonly prohibited around paintings for good reason. Restrictions, permitted equipment and any charge for video are set by the authority managing the site and change from time to time, so the current position at that gate is the only reliable one.

Finally, these are large sites with a lot of steps and very little shade between the excavations. Allow much more time than the map distance suggests, start early, and accept that seeing a dozen caves properly is a better day than seeing thirty of them at a walk.