In my mind, the images of the British Isles in the ’60s are musical. I envision rock and roll bands with color-coordinated suits, meticulously messy hair and electric guitars descending on London and transforming Western culture. I imagine the Rolling Stones playing at Hyde Park to the youthful masses, and The Who stuttering their way through generational anthems. I do not imagine the barren landscapes of northwestern Ireland or thousands of middle-aged, middle-class families vacationing on the English Channel. The Yale Center for British Art’s new exhibition “Bruce Davidson/Paul Caponigro: Two American Photographers in Britain and Ireland,” then, came as something of a revelation.

The exhibition combines the black-and-white photographs, produced by hand in darkrooms, of the two American photographers, both of whom worked throughout the British Isles in the 1960s. Caponigro’s landscapes, taken with funding from a Guggenheim Fellowship, focus on the megalithic monuments and cairns that dot the hills of Ulster and Connaught; Davidson, sponsored by The Queen magazine, instead turned his camera on the un-glamorous aspects of middle-class and working-class life. Moving from Caponigro’s works to Davidson’s is to move from the unknowable mysticism of the ancients and the early Christians to stark portraits of mass culture in the waning days of traditionalism, before the great Sixties cultural revolution.

Caponigro’s photographs, essentially, are of stones. Only in a few do humans appear. These stones come as cairns, as churches, as megaliths and tombs. The two photographs of Kilclooney Dolmen in County Donegal on the far northwestern fringes of Ireland are his most effective. Some of its compelling nature derives from the oddity of the subject — one massive moss-covered stone balances horizontally on top of four others. The near-silhouette against the ubiquitous grey sky makes the points of contact seem unfathomably small. Nothing but desolate hillside and windswept grass surround the dolmen. One cannot help but marvel at the ingenuity of the ancient tribes. That is the effect of most of Caponigro’s photographs — sheer astonishment that peoples so primitive in building techniques constructed monuments that have lasted for five millennia.

Davidson’s works are especially brutal in their undisguised realism. This is Britain — unromantic, bleak and often depressing. From that realism derives the effectiveness of the Davidson half. I find Caponigro’s photographs more beautiful, but I spent far longer with Davidson’s dozen photographs of South Wales coal mining communities. In one, a soot-faced miner stands in the Spartan doorway of his house holding his infant child. In another, a group of five men, their filthy clothes ripped and torn, walk along a dirt path, their mine visible far behind them. In a third — this the most memorable photograph — a miner stands on a treeless hillside, his arms crossed defiantly over his white shirt. Two others, their forms dark and indistinct against the grey sky, stand by a cart in the background. With them are two horses. These are the most poignant photographs in the exhibit; hanging over each of them is the heavy, inescapable burden of history. Partly, this derives from my own knowledge — that Brighton and Blackpool are no longer quite so popular, that the South Wales coal mines all  shuttered under Thatcher. It’s like staring straight into the eyes of something about to end after a thousand years and seeing it stare right back. The effect is profoundly haunting and the photographs return far more easily to my mind than does the remainder of Davidson’s half of the exhibit, much of which I found forgettable.

In the end “Two American Photographers” forces us to consider uncomfortable, penetrating questions. Caponigro’s collection presents the monuments of a far-bygone age: These monuments, pagan and Christian alike, essentially consist of no more than stacked stones, yet have lasted for millennia in harsh, unforgiving terrains. Still we have little idea of what exactly all those stones mean, and Caponigro’s portrayal makes them seem even more unknowable. Davidson, meanwhile, presents modern life, but a sense of twilight permeates throughout his work. We are left with a lingering question, conveyed through the sullen eyes of the coal miners and their children: What will remain? Caponigro has shown us what the ancient Irish left behind, but what will remain from our era? It is an uncomfortable question, and Davidson offers little help in answering it — after all, his photographs show the sort of pre-1960s mass culture that has largely failed to survive even the last 50 years. Permanence and ephemerality coexist in this moving exhibit, and the thought that nearly all of what we have built will one day vanish is indeed a frightening one.