There are lots of differences between the two encampments now thoroughly established in downtown D.C. The one on Freedom Plaza has been in the works since this spring, in anticipation of the 10th anniversary of the war in Afghanistan, while the one in McPherson square—-a.k.a. Occupy K Street—-arose in response to the spontaneous takeover of Zucotti Park in New York City. Freedom Plaza has an extended permit from the National Park Service, while the residents of McPherson Square have none at all. Freedom Plaza represents an older generation of left-wing activists still rooted in opposition to Vietnam, while Occupy K Street is the new guard, learning and drawing strength from the rest of the movement through every kind of social media imaginable.

But the most important difference? The ground they stand on.

All public spaces are not created equal, as we know. And Freedom Plaza, a vast expanse of concrete inlaid with representations of the White House and the Capitol Complex, is about as livable as a barren tundra. Tents have overflowed the small grassy patches, and are resting on hard concrete. Communal services, like food, medical supplies, and media, are clustered in a corner; the central walkway between them is narrow and divided by a staircase, which makes it difficult to navigate. The evening gathering, called General Assembly, can only occur in the middle of the plateau. Although this has changed recently, for much of the time they’ve been there, the facilitator spoke using a mic in front of a bunch of chairs arranged in rows—-not the most democratic way to hold a meeting.

Most devastatingly, there’s nothing of much value around the plaza. There’s the fortified wall of the Reagan building, the usually dark National Theatre, a blank office building, and the monumental staircase of D.C.’s city hall—-not the people these protesters are targeting. There’s no reason for passersby to go through the plaza unless they’re curious about something inside it. All in all, a lonely place to hold an occupation.

Now, consider McPherson Square. It’s a much more traditional park, symmetrically organized around a central statue, spacious but not big enough to get lost in. There’s much more earth than concrete, which allows something of a separation between the “residential” and more transitory concrete spaces. Rather than ranks of chairs, meetings are held in circles sitting down on the grass, lending them an intimacy Freedom Plaza could never offer. The communal tents line both sides of a “street” that people would naturally walk through, browsing at the lending library, sitting on a bench, or stopping to chat at the information station without getting in anyone’s way. The mature trees serve both as landmarks—-“meet by that oak,” you might say—-and as shelter from both the sun and the rain. It’s surrounded by restaurants, residences, hotels, and offices that are all open to the street, creating a natural circulation of people who stop and stay a while on their way to lunch or appointments or the metro.

In short, it’s urban—-closer to the heart of the living city than Freedom Plaza’s location in the midst of federal sterility, and much better suited for the kind of community the occupiers are seeking to create. The movement, as I understand it, isn’t as much about message as it is about modeling the way they’d like society to work. As Times architecture critic Michael Kimmelman put it, it’s a polis, open to all, where consensus is achieved through an “architecture of consciousness.”

Regardless of what you think about their politics, both occupations are a vast improvement over the typical state of those parks. They’re much more public spaces, put to excellent use as hubs of 24-hour activity rather than dead zones.

But both will have to end eventually, and I wouldn’t be surprised to see Freedom Plaza end first, because it’s just not as attractive a place to live. And living is basically what this whole thing is about.

I’m working on a longer column about this for next week’s print edition. Get in touch if you feel like it.