Underland — A Deep Time Journey

Descent

Macfarlane’s previous books went up (mountains) and across (paths). This one goes down. The book is structured as a series of descents — into cave systems, into the Paris catacombs, into the darkness under Somerset, into a Finnish nuclear waste repository that is being built to last 100,000 years.

The structural choice is also a thematic one: going underground means going deeper in time. The caves contain traces of early human ritual — Macfarlane finds art made 40,000 years ago. The nuclear waste repository contains a different kind of trace — the problem of leaving a warning that will still be legible in 100,000 years’ time, when no current language will remain.

The Anthropocene Underground

The Finnish section is the book’s moral and intellectual centre. How do you mark a site as dangerous for 100,000 years? What symbols, what materials, what structures might survive and still communicate? The question is disorienting because it forces you to think from outside the human scale.

Macfarlane’s Larger Project

Underland is the culmination of a body of work Robert Macfarlane has been building since Mountains of the Mind (2003), the book that announced him as the most significant British nature writer of his generation. Across The Wild Places, The Old Ways, and Landmarks, he developed a recognizable method: travel on foot through a landscape, braid the journey with literary, geological, and folkloric history, and attend obsessively to language — the lost vocabularies of place that Landmarks set out to recover. Underland turns that method downward and, in doing so, raises the stakes. Where the earlier books were elegies for vanishing ways of moving through the world, this one is an attempt to think at scales — geological, planetary, deep-time — that exceed the human entirely. It is the most ambitious and the most haunted thing he has written, and it won wide acclaim on publication, including selection as a notable book of the year by numerous publications and recognition among the most important environmental writing of its decade.

The Network Beneath

One of the book’s quietest revelations is its account of the “wood wide web” — the mycorrhizal fungal networks that connect the root systems of a forest, allowing trees to share nutrients and chemical warnings underground. Macfarlane uses this as more than a botanical curiosity: it becomes an image for the book’s whole argument that what lies beneath is not inert but alive, communicative, and interdependent in ways the surface conceals. The same attentiveness applies to the dark matter detectors buried in Yorkshire mines, the meltwater moulins of Greenland, and the bone-strewn caves of the Mendips. Each underland is a place where the human story is dwarfed by something older or stranger, and where the boundary between geology and biology, between the made and the found, dissolves. This refusal to treat the underground as merely dead rock is what gives the book its uncanny charge.

The Weight of Deep Time

The Finnish repository at Onkalo crystallizes the book’s deepest unease. To bury nuclear waste for 100,000 years is to make a promise to a future so distant that no human language, no nation, and possibly no species continuity can be assumed. Macfarlane lets that vertigo work on the reader rather than resolving it, and the section reads less like reportage than like a meditation on responsibility across spans of time the mind was not built to hold. It is here that the descent metaphor pays off most fully: going down has been, all along, a way of confronting what humanity is leaving behind. The book asks not only what we have made but what trace of us will remain, and whether that trace will be a warning or a wound.

Limitations

The opening Somerset cave section is less compelling than what follows, in part because it has to establish the descent conceit before the stakes have fully gathered. The book is long — at nearly 500 pages the pacing occasionally flags, and Macfarlane’s lyricism, so effective in concentrated doses, can grow dense over sustained stretches. These are worth knowing before starting, though they are unlikely to diminish the experience for the readers the book is written for, who will likely find even the slower passages rich enough to reward rereading.

How to Read It

Underland rewards patience and a willingness to let its chapters accumulate rather than rushing for a thesis. It is not a single argument but a sequence of descents, and its meaning emerges from the resonance between them — the Paris catacombs speaking to the Slovenian karst, the Greenland ice to the Finnish bedrock. Readers new to Macfarlane might find an entry point in his shorter, sunnier The Old Ways before committing to this denser, darker book, though Underland can absolutely be read first. It pairs naturally with Elizabeth Kolbert’s The Sixth Extinction and with the deep-time writing of John McPhee. Above all it asks to be read slowly, the way one would move through an actual cave: carefully, by lamplight, alert to the strangeness pressing in from all sides.

Who This Is For

Readers of literary nature writing and environmental thought — anyone interested in deep time, the Anthropocene, and what humans have made and unmade. Those who admired Rebecca Solnit’s reflective essays or Barry Lopez’s Arctic Dreams will recognize a kindred sensibility, and anyone troubled by climate change will find in the Onkalo chapters a way of feeling the crisis at a scale that data alone cannot convey.

Our rating: 4.4/5 — Macfarlane’s most ambitious book — descent into deep time and the disturbing weight of the Anthropocene.

Reading Guides

• Where to Start with Robert Macfarlane
• The Old Ways by Robert Macfarlane — Full Review