Some images never grow old, never fade in color on that screen of our life that lives at the back of the mind. Some of the images that live on for me were created 18,000 years ago, in southern France.

I remember the first time I saw ever saw cave painting art. I was a young art student and eager to soak up everything while hitchhiking through Europe and Asia with my best friend, devouring every museum and monument to visual culture with an energy and appetite typical of the 18 year olds we were. We spent two solid weeks systematically studying every gallery in the Louvre, camped our way down the Turkish coast to the ancient site of city of Troy, wandered through the Casbah in Algiers, sat on the stones of Stonehenge before anyone had the good sense to preserve that Neolithic treasure from the wear and tear of careless tourists like us.

But the cave paintings at Les Eyzies-de-Tayac-Sireuil in France. That was something of a completely different order. Primal and yet elegant, ancient and yet timeless, overwhelming in its scope and yet so intimate and personal. I was stunned how the painters (many experts believe that these images were actually made by women for reasons that I won’t elaborate here) incorporated the topography of the cave surface into the paintings—an actual “hump” in the wall becomes the hump of a beast’s back.

The legendary caves at nearby Lascaux were discovered in 1940 but had to close down in 1963 due to damage from the breath of visitors. Later on I toured the ambitious replica that was created alongside the original cave and found the images spectacular. And of course big discoveries have happened since then, most spectacularly the cave at Chauvet-Pont-d’Arc.

Thanks to Sally Reed for flagging a set of “unpublished” images from Lascaux on Life. The slide show’s intro:

A warm afternoon in southwestern France. As two schoolboys hunt rabbits on a ridge covered with pine, oak, and blackberry brambles, their dog chases a hare down a hole beside a downed tree. Widening the hole, removing rocks, the boys follow — and enter not merely another world, but another time. Underground, they discover “a Versailles of prehistory” — a series of caves, today collectively known as Lascaux, boasting wall paintings up to 18,000 years old. In 1947, LIFE’s Ralph Morse went to Lascaux, and became the first photographer to ever document the astonishing, vibrant paintings. Here, on the 70th anniversary of the discovery of the cave and its treasures, in a gallery featuring rare and never-published photographs, Morse — still vibrant himself at 93 — shares with his memories of what it was like to encounter the long-hidden, strikingly lifelike handiwork of a vanished people: the Cro-Magnon.