Joggins, Nova Scotia grew from cliffs lined with seams of coal: ancient plants transformed to combustible stone.

Acadian miners began burrowing into the bluffs three hundred years ago. A century ago, English ships arrived to take fuel back to a country gridlocked in trench warfare. They brought no goods to exchange, so filled their holds in Europe with a ballast of multicolored stones, which they dumped as soon as they docked. The rocks’ once-jagged edges are now eased by a century of rolling up and down the endless strand, high tide to low.

A few tattered logs mark the end of the old wharf. The trestle that carried ore cars to the bay has vanished, but a drainage shaft still vents water from the mine, painting the stone coppery red from the equipment left inside to rust. Tools wash out when the water’s high, hammers and blasting caps set down in the 1920s and never touched again, unless by bats or the blind things that live in caves, or by ghosts.

Ghosts haunt the cliffs too. Ancient trees, segmented like horsetails, stand in silt long turned to stone. The oldest terrestrial creature ever recorded—the first thing scientists have found that heaved itself out of the primeval sea—was discovered here, curled in the petrified hollow of a burned-out stump. Accounts of this place scaffolded Darwin’s theories of evolution.

The land’s too old for dinosaurs, but there are spiders and scorpions, horseshoe crabs and finned fishes, seven-foot long millipedes and amphibians the size of crocodiles. Rock sloughs from the cliffs under the waves’ assault and shatters on the ground below, continually exposing and destroying the fossils tucked inside.

The guide invites our kids to climb on rocks, handle the fossils, even throw them out to sea. “They won’t hurt them,” she says, though of course that’s not true. It’s more that she recognizes the inevitability of destruction. It’s a truth we often evade, but it’s laid bare here, in this land of gray rock and treacherous water, under a changeable sky.

The other visitors stay near the stairs. We walk forward across a million years of history as the sea pulls back along fins of stone to our right. No one has come here since yesterday afternoon, and in that time, the ocean has risen twice, covering all land nearly to the edge of the cliffs. We are the first to walk here since it has receded.

My daughter’s pink raincoat flares against the pewter landscape. We turn a corner and find a section of a tree high up in the cliff. The rock facing it has fallen, imprinted with the negative image of its striated bark. My son sits on it, staring up.

Later, my husband will show a picture to a guide at the museum. He will tell us that the piece that fell off—our son’s seat—did so since yesterday. The tree it revealed is rare. Maybe a paleontologist will trace the history of a species in its mineralized cells. It might merit a mention in a paper, be pointed out to visitors on ranger walks. But in this moment, it feels as if it belongs only to us.

My son runs a fingertip along the bark, tracing the echoes of life three hundred million years old. In another hour, we’ll be gone. In a few weeks or months, the tree itself will fall onto the beach, to be sucked at by the restless waves.

Erin Ruble’s essays and short fiction have appeared or are forthcoming in Fourth Genre, Boulevard, River Teeth, and elsewhere. She lives in Vermont with her husband and children. You can find her at erinruble.wordpress.com.