Every previous Macfarlane book has been about going up or out — mountains, coasts, paths. *Underland* goes down. Into the bedrock caverns of Yorkshire, the glacial ice of Greenland, the catacombs of Paris, the ancient painted caves of Slovenia, the nuclear waste repository of Finland. It is his most ambitious and most disturbing book — and his best.
The Underland
Macfarlane organises the book around three functions of the underland: it is where we send things down for safe-keeping (seeds, gold, data), where we go down to find things of value (minerals, aquifers, ancient art), and where we send things down to be forgotten (nuclear waste, toxic chemicals, the dead). Each journey explores one of these functions.
The prose descends as the book proceeds. The early chapters — English caves, Norwegian fjords — are recognisably Macfarlane, lyrical and landscape-attentive. By the final chapter, in a Finnish nuclear repository designed to remain sealed for 100,000 years, the writing has become darker, stranger, and more genuinely unsettling than anything he has written before.
Deep Time and Nuclear Waste
The book’s philosophical centrepiece is the Finnish repository — the Onkalo facility near Rauma — designed to contain high-level nuclear waste for longer than recorded human history. The designers faced a problem: how do you warn future civilisations, whose languages and symbols you cannot predict, not to dig here? How do you communicate danger across 100,000 years?
Macfarlane uses this problem as a lens for thinking about deep time, intergenerational responsibility, and the hubris of a civilisation that generates waste it cannot neutralise in any timeframe meaningful to human experience.
We tend to think of deep time as liberating, but it is also a pressure: we are brief sparks in a great darkness, and the darkness was here long before us and will be here long after.
— Robert Macfarlane, Underland
6 Key Ideas From This Book
Understanding geological time — the immensity of what came before us and will come after — is not merely interesting but politically necessary. Civilisations that cannot think in deep time make decisions that are catastrophic on that scale.
The Greenland chapters document the science of ice cores — cylinders of ancient ice containing bubbles of atmospheric gas from hundreds of thousands of years ago, a direct record of past climates. The ice Macfarlane stands on is actively disappearing, taking the archive with it.
A chapter on the wood wide web, seen from underground perspective — the fungal networks through which forests communicate and share resources. Macfarlane's account is informed by direct conversation with Suzanne Simard and Merlin Sheldrake.
Macfarlane spends time in total underground darkness, and the book is in part an investigation of what darkness does to perception and cognition — how the absence of visual input sharpens other senses and changes temporal experience.
The chapter on prehistoric cave art — the Chauvet paintings made 36,000 years ago — asks what it means that our deepest artistic impulse led humans underground. The oldest human art is hidden from sunlight, addressed to nobody, preserved by darkness.
The nuclear repository designers are grappling with the most extreme intergenerational ethics problem imaginable: how to protect people 100,000 years from now from our present decisions. This chapter makes the concept of intergenerational responsibility viscerally real.
Any Weaknesses?
The book is very long and the tonal descent — from lyrical landscape writing to something much darker and more anxious — may feel like two different books to some readers. The final chapters, deliberately disturbing, are very different from the opening sections.
Macfarlane’s intellectual range occasionally results in chapters that feel like separate essays rather than a continuous work. The Paris catacombs chapter, while fascinating, sits uneasily with the book’s larger themes.
Readers who have followed Macfarlane's career and want his fullest, most ambitious work — and who are ready for a book that gets darker as it proceeds.
The Wild Places by Robert Macfarlane for his earlier, lighter register, and Entangled Life by Merlin Sheldrake for the mycorrhizal science Macfarlane explores from above in this book.
Nuclear engineers and waste management professionals. The Onkalo chapter is the most searching account available for a general audience of the ethical dimensions of long-lived radioactive waste.
The book is intentionally unsettling by the end. Read the Greenland and Finland chapters slowly and in order — their full weight depends on what precedes them.
Frequently Asked Questions
Is Underland worth reading?
Underland is Macfarlane's masterwork — more uncomfortable and less beautiful than his earlier books, but more necessary. It asks what we owe the deep future and what we have already sent down into the earth we cannot recall. The answer is not reassuring, and the book does not pretend otherwise.
Who should read Underland?
Readers who have followed Macfarlane's career and want his fullest, most ambitious work — and who are ready for a book that gets darker as it proceeds.
What is Underland about in one sentence?
Every previous Macfarlane book has been about going up or out — mountains, coasts, paths.
The Verdict
*Underland* is Macfarlane's masterwork — more uncomfortable and less beautiful than his earlier books, but more necessary. It asks what we owe the deep future and what we have already sent down into the earth we cannot recall. The answer is not reassuring, and the book does not pretend otherwise.
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