The street as canyon and landmark: why the alignment feels like an event

The sun lines up with thousands of streets. It comes straight down suburban arterials and farm roads and the gaps between big-box stores and the flat avenues of a hundred subdivisions, on a schedule every bit as exact as Manhattan's, and almost none of it turns into anything. Nobody drives out for it. Nobody gives it a name. The camera stays in the bag. So the real puzzle of the henge was never why the sun lines up with a street, which the pieces before this one have already answered. It is why the sun coming down this street, and not the one a block over, feels like something worth stopping for. That is not a question you can answer with a bearing. It is a question about the street, and the people who thought hardest about it were not astronomers. They were a handful of twentieth-century writers on cities, Spiro Kostof and Kevin Lynch and Gordon Cullen and Christopher Alexander, and this piece is about what they can tell you that a number cannot.

The canyon: why the same sun looks like more between tall walls

Start with the plainest part of it, which is physical. The reason Manhattanhenge looks like a wall of fire and the same alignment on a wide suburban road looks like a decent sunset is the buildings, and more exactly the ratio between how tall they stand and how far apart they are. Kostof, in The City Assembled, describes how nineteenth-century reformers came to see the street as a section, a profile of its width against the height of the buildings on either side. "Congestion," he writes, "was perceived in terms of street width and the overall height of flanking buildings. Narrow, canyon-like streets kept sunlight from reaching ground level." The thing those reformers most wanted to legislate out of existence, with height limits and mandated widths, was the exact thing that makes a henge worth watching: a deep narrow slot of a street where the sky is squeezed down to a bright ribbon overhead and the buildings lean in from both sides.

The same low sun, two streets. Between tall, close walls it becomes a bright slot, a wall of light with edges; across a wide, low street it is just a sunset with open sky on every side. The drama is made by the buildings, not the sun.

This is why the henge is really an urban thing and not just a solar one. The alignment supplies the light. The canyon supplies the frame. A tall narrow street does two things to a low sun that an open one cannot. It keeps the sun hidden until the moment it lines up, so the light shows up all at once instead of fading in across a whole open horizon. And it clips the glow into a hard vertical shape held between the building faces, so a soft sunset turns into a bright thing with edges, almost a piece of architecture. Manhattan is the far end of the scale, its cross-streets walled in by even, tall frontage for miles, and that is why its henge is the one everybody photographs. The trigonometry is the same everywhere. The canyon is what makes it read.

The path and the landmark: why some streets stick in the mind

The framing tells you why the light looks dramatic. It does not tell you why one particular street becomes the one people remember and come back to. For that, Kevin Lynch's The Image of the City has the vocabulary. Lynch sat down with city residents and asked how they actually carried their cities around in their heads, and he found that people build the mental map out of five kinds of thing: paths, the channels they move along; edges, the boundaries; districts, the areas; nodes, the junctions; and landmarks, the fixed memorable points they steer by. A city that is legible, in his word, is one whose elements are clear and easy to hold. A forgettable one is where they all blur together.

Lynch's five elements of the city image. A henge street is unusually strong on two of them at once: it is a path, a channel you move along, and at the aligned moment it acquires a landmark, the sun itself framed at the street's end, making the whole corridor briefly one of the most legible things in the city.

A henge street scores high on two of those at once, which is a rare thing for a street to do. It is obviously a path, a long straight channel of movement, the kind of thing people use to organize a whole district in memory. And for a few evenings a year it picks up a landmark, in the most literal sense Lynch means, a distinctive fixed memorable point that closes the view and lines everything up around it. The landmark just happens to be the sun. A street that is usually only a path, a way of getting somewhere, becomes for those few minutes a path with a landmark at the end of it, which is more or less Lynch's recipe for the most memorable kind of urban space there is. That is a good part of why people can tell you exactly where they were standing for a henge and not for an ordinary sunset. The event writes itself onto the mental map, because for a few minutes the street is as legible as anything in the city.

Serial vision: the walk is the event

There is a third writer whose main idea lands on the henge almost too neatly, and it moves the whole thing from the still picture to the moving body. Gordon Cullen, in The Concise Townscape, built his account of the city around what he called serial vision. A city is not taken in as a plan seen from above. It is taken in as a run of views opening up one after another to a person walking through it, each bend and each narrowing showing you something the last view kept back. Cullen was after the drama of the here and the there, the tug a walker feels toward whatever the next stretch of street is about to give up.

Cullen's serial vision applied to a henge. The payoff is not any single frame but the sequence: the corridor with nothing in it, the first blade of light edging into the gap, and then the sun filling the street's end. The experience is the reveal, which is why walking toward a henge beats arriving already parked at it.

This is the most literal match in the whole library between a theory of cities that already existed and what a henge actually feels like. Walking up to a henge is serial vision with the sun as the payoff. You come down the street with the alignment still hidden behind the buildings or a slight bend. The light works its way into the slot. And then, over a few dozen steps, the sun swells into the full width of the corridor and fills the far end of the street. The event is not really the instant of the disc sitting on the centerline, the thing a photograph freezes. The event is the reveal, the light coming into view as you move, which is why standing on the spot from the start is a thinner experience than walking up to it. Cullen gives you the reason a henge is a thing you go to, on foot, and not just a thing you look at.

Why a street becomes a place to gather

The last piece is the least technical and the most human. It is why the henge turns social, a thing crowds do together instead of something people notice on their own. Christopher Alexander's A Pattern Language lists, in its numbered patterns, the features that make some public spaces pull people in and hold them while others sit empty. Patterns like Promenade and Activity Nodes and Path Shape describe, in plain words, why a particular street becomes a place people choose to be, event or no event: it has a clear direction and a clear destination, it gathers activity instead of spreading it thin, its shape asks you to walk its length. A henge street is very often already that kind of street. The qualities that make a corridor a good promenade, a long legible path toward a clear end, are the same ones that make it a good henge stage, and the same ones that make it a place people already want to be. The alignment just gives the promenade a reason and a time.

Put the four of them together and the puzzle the piece started with comes apart on its own. The sun lines up with any number of streets, but a henge needs more than the alignment. It needs a canyon to squeeze the light into something with edges, in Kostof's terms. It needs to be a path strong enough to carry a landmark, in Lynch's. It needs to pay off the walk toward it, in Cullen's. And it needs to be the kind of promenade people already want to stand on, in Alexander's. The suburban arterial has the same sun on the same schedule and none of that, which is why its perfect alignment goes by without a single person turning to look. The henge is not the sun finding a street. It is the sun finding one of the few streets that was already, for reasons that never had a thing to do with the sky, a place worth standing in.

Sources

• Spiro Kostof, The City Assembled: The Elements of Urban Form Through History (Bulfinch and Thames and Hudson, 1992), read directly for this piece. The passage on congestion perceived through street width and flanking height, and the phrase "narrow, canyon-like streets kept sunlight from reaching ground level," are from the book's discussion of the street and public health reform. The straight-street and terminated-vista vocabulary is from the companion volume, The City Shaped (Thames and Hudson, 1991), also read directly.
• Kevin Lynch, The Image of the City (MIT Press, 1960), for the five elements of the city image (paths, edges, districts, nodes, landmarks) and the concept of legibility. The five elements and the path-versus-landmark framing are Lynch's well-known central argument.
• Gordon Cullen, The Concise Townscape (Architectural Press, 1961), for serial vision and the "here and there" of the walked city.
• Christopher Alexander and others, A Pattern Language (Oxford University Press, 1977), for the patterns (Promenade, Activity Nodes, Path Shape) that describe why some streets draw and hold people.
• The framing of the henge as an urban rather than purely solar phenomenon, and the role of building height and street width, is this series' own synthesis of the above; the specific claim that Manhattan's tall consistent frontage makes its henge the most photographed is general observation, not a cited figure.