The wall that divides Berlin is hard to visualize, because it defies comparison. Other things in the city are easy enough to imagine, because they can be Iikened to something familiar—the Kurfürstendamm to Fifth Avenue, Potsdamer Platz (in an earlier period) to Times Square, the Spree River to the East River, and so on. But there has been never been anything quite like die Mauer—or, as Mayor Willy Brandt has called it, die Schandmauer (the wall of shame). Its purpose alone would make it unique. Countries have built walls to keep their enemies out; die Mauer is probably the only wall ever built to keep a people in. Physically, too, it is in a class by itself. Unlike the Great Wall of China, Hadrian’s Wall, and other walls that have figured in history, it is an engineering and architectural laughingstock. It isn’t even very long, as famous Walls go. The Great Wall stretched for fifteen hundred miles, Hadrian’s for almost seventy-five. Die Mauer is only twenty-seven miles over all. It runs along the sector border—the line that was drawn approximately through the center of Greater Berlin in 1945 by the Four Powers to mark off the Soviet and Allied occupation areas—and since the sector border, which follows some of Berlin’s old borough borders, is even more eccentric than most territorial boundaries, the wall runs a highly irregular course, going for a certain distance in one direction, veering off in another, curving slightly here, making a ninety-degree turn there, cutting through parks, squares, cemeteries, factory lots, and waterways, and continuing thus on its ragged way. It is anything but uniform in construction. In outlying sections of the city, it consists mainly of two ten-foot-high barbed-wire fences spaced about six feet apart. Along several streets, it is a row of vacant apartment houses whose doors and windows have been bricked shut. For a few blocks, it incorporates a red brick wall bounding one side of a cemetery, and for more than a mile the Spree serves as the wall. For the most part, though, it is made of materials originally intended for housing construction—a circumstance that contributes to its generally implausible appearance. At the base of the wall, there is usually a row of upright prefabricated concrete slabs about four and a half feet square and a foot thick. These were not set into excavated foundations but merely laid on the ground. As a result, when the ground heaved during last spring’s thaws the wall fell down in a few places, and East German workers had to put it up again. On top of the slabs there may be a couple of rows of regulation-size concrete building blocks and, above them, a piece of smoothly finished concrete about thirty inches long and twelve inches square. All these blocks and slabs are held together with mortar that drips messily down the sides. Surmounting the structure at intervals of about three feet are Y-shaped pieces of metal, on which are strung strands of barbed wire that have become rusty. These are the usual components, but they are not always assembled in the same way. Sometimes, the master builders slapped a second piece of finished concrete on top of the first. Other times, they didn’t. Occasionally, they put up a stretch using building blocks exclusively. Not surprisingly, the wall varies a good deal in height. As a rule, it is about ten feet high, but in some places it is twice that, and it may vary by a couple of feet as many as three or four times in the course of a city block. There is, however, one consistent thing about the wall, and that is shoddy workmanship. It looks, as a Berlin sculptor has remarked, as if it had been thrown together by a band of backward apprentice stonemasons when drunk.