Last summer, I saw the multiverse open up. It happened in the wilds of Dumfries and Galloway, near Crawick, 50 miles (80km) south of Glasgow. It was June, but the multiverse was rather cold and rainy. Still, I do recommend that you go to see it for yourself. Take your boots.

The Crawick (pronounced "Croyck") Multiverse is not a rift in space-time, but a landscape sculpture by architect and designer Charles Jencks. Constructed from the debris of a former coal mine, the 22-hectare (55 acre) site is a project of baroque ambition, speaking at the same time to the mysteries of Neolithic monuments and to the current speculations of cutting-edge cosmology.

There are all manner of strange objects to explore: spiralling tumuli, crescent-shaped lagoons, cryptic inscriptions, amphitheatres and tomb-like chambers. But much more than a system of strange earthworks, the Crawick Multiverse is a representation of our current ideas about the universe – and of the possible other universes that some theories predict to exist, but which, by definition, we cannot see.

Jencks is no stranger to this kind of grand statement.

His house near Dumfries, about 30 miles (50km) south of Crawick, sits amidst the Garden of Cosmic Speculation: a landscape of undulating terraces, water pools and ornate metal sculptures representing all manner of scientific ideas. A terrace shows the space-time-bending antics of black holes, sculptures represent the helical forms of DNA, and lakes and landforms illustrate mathematical fractals.

Jencks also designed the lawn in front of Edinburgh's Scottish National Gallery of Modern Art, a series of crescent-shaped stepped mounds and pools inspired by chaos theory and, in his words, by "the way nature organises itself".

Jencks also has a plan for a landscape at CERN, the European particle physics centre near Geneva, which is currently awaiting funding.

The Multiverse project began when the Duke of Buccleuch and Queensberry – whose ancestral home of Drumlanrig Castle is near Crawick – asked Jencks to reclaim the site. It was dramatically surrounded by rolling hills but disfigured by slag heaps from open-cast coal mining.

When work began in 2012, the excavations unearthed thousands of boulders half-buried in the ground. Jencks used them to create a panorama of standing stones and sculpted tumuli, organised to frame the horizon and the Sun's movements.

The landscape explores the idea that our Universe is just one of many

"One theory of pre-history is that stone circles frame the far hills and key points, and while I wanted to capture today's cosmology, not yesterday's, I was aware of this long landscape tradition," Jencks says.

The landscape also explores the idea that our Universe is just one of many.

Over the last decade or so, the argument for a plurality of universes has moved from fringe speculation to seriously entertained possibility. One leading multiverse theory supposes that other universes are continually being spawned in an ongoing process of "eternal inflation" – the same that caused our own Universe's Big Bang 13.7 billion years ago.

These are the theories explored on this Scottish hillside.

The Multiverse itself is a mound up which mudstone slabs trace a spiral path. Some of the slabs are carved to symbolise the other universes that eternal inflation predicts, where different physical laws apply.

Meanwhile, two corkscrew hillocks represent our own Milky Way galaxy and its neighbour the Andromeda galaxy, both of which belong to a cluster called the Local Group.

"But where did they come from? From the supercluster of galaxies," Jencks says – which are represented in the landscape by a gaggle of rock-paved artificial drumlins.

"And where did they come from? From the largest structures in the universe, the web of filaments. And so on and on."

Jencks says that he wanted "to confront the basic question which so many cosmologists raise: why is our universe so well-balanced, and in so many ways? What does [this] apparent fine-tuning mean? How can we express it, make it comprehensible, palpable?"

The issue of fine-tuning is one close to cosmologists’ hearts. If the laws of physics were changed even slightly, there would be no stars, planets or life – an argument that has been used in favour of the existence of God. A multiverse could be the atheist’s answer. If a multiverse exists, with each universe having a different set of laws, we don't need a God to have carefully arranged our universe to suit us; it’s just that we live in one of the life-friendly versions.

But the main aim of the Crawick Multiverse is not to disprove God’s existence or even to "teach" the science of the universe: it is to restore some meaning to this site of mining-induced desolation, using primarily local materials.

Like the medieval cosmos encoded in Gothic cathedrals, this sort of architecture is primarily symbolic

After all, the theories themselves are provisional. They will surely look quite different in 20 years, as will the earthworks once they have had a chance to bed themselves into the landscape.

Instead, like the medieval cosmos encoded in Gothic cathedrals, this sort of architecture is primarily symbolic. It speaks to us through what art historian Martin Kemp has called "structural intuitions": innate familiarity with the patterns of the natural world.

Some scientists might look askance at any suggestion that the Crawick Multiverse can be seen as a sacred place.

But walking into the Multiverse, even the most secular of scientists must feel some of the awe that a peasant must have experienced on entering a medieval cathedral – and stepping into its cosmic labyrinth.

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