Walls! Why do we see high walls and fences all over town? Suddenly, some of our most graceful residential streets are lined with high barriers, blank walls of masonry or wood, denials of the very concept of neighborhood.

Don't give me Robert Frost. The walls that make good neighbors that he described were those lovely, waist-high stone walls that delineate private property, not these symbols of hostility, these feudal relics.

"But," says a friend as I fulminate on this subject, "aren't these people just looking for a bit of privacy?"

Yes, probably that's what they have in mind. But this is the privacy of 16th-century strongholds, built to defend property from marauding gangs or hostile armies. And privacy, if that's the goal, can be found inside your castle or in its backyard. Front yards in developed urban neighborhoods should be part of the public arena-shared space, at least in the visual sense. They defend our property by defining our ownership, not by creating a symbolic moat against the barbarians. And really, despite the temptation to so characterize the unruly traffic and occasional bad guy out there, we do not live in a society in which survival dictates hiding behind barricades. Besides, anyone who really wants to break into a home will probably be able to do it, wall or no wall, assuming you haven't invested in razor wire, searchlights and sirens.

So why are the walls proliferating? Ask the owners and they may tell you that they want to protect their children, their pets and their private lives from the noisy perils of the street. But why is the street noisy? Why does traffic move too fast? And why must we worry about our children, indeed about ourselves, in our own neighborhoods?

Perhaps it's precisely because we are so isolated that we can't watch out for each other or for what's happening in the street. The increasing disconnect between traffic and our living space invites insensitive speed and noise, and hiding from each other invites suspicion and hostility.

Neighbors who know each other-we're not insisting everyone be friends-tend to look out for each other. Families who see the neighborhood children as they walk, play and bike on the streets will also see danger or threats to those children and will report the problem to their parents or the appropriate authority. But you can't see those children or those dangers from behind a wall. Of course, you could keep your children and your pets inside the "compound." But what kind of life is that? How does that build neighborhood cohesion? How does that make us safe?

In this context, it's fair to consider the traditional courtyard home, the house that faces inward, creating private space within. Some very graceful architecture comes from this tradition, starting with the houses in Pompeii; and such homes are still found in Spain and South America. But these are usually houses in the midst of the crowded city, built up to the street, not the suburban compounds that lurk behind these new walls. Along Orange Avenue, you can see some good examples of small entrance courtyards that shelter a house's access area without cloaking the entire structure in a high barrier. But there are many more examples of houses set back from the street but isolated in an empty walled forecourt.

The walls I deplore are those that have been thrown up in front of many typical Sarasota houses. You see them, long, blank structures along such neighborhood streets as Orange and Osprey. You don't, however, see as many on two other neighborhood streets that are also important north-south arteries-Tuttle Avenue and Beneva Road. Those streets have fewer walls and more hedges and picket fences, forming a much friendler frontier to private domain.

Yes, the speed limit on Orange and Osprey is probably too high, but traffic also moves more quickly when drivers can't see human activity along the route. At certain points on Osprey, particularly south of Hillview, the line of high fences and masonry walls creates a visual tunnel, inviting speed.

It's natural to mark the limits of our territory. Animals do it by marking trees and lamp posts; and until recently, civilized folk have done it with low stone walls, or picket fences, or hedges. After all, if the intent is to indicate boundaries, the transition from public to private space, a waist-high structure will do just fine. From the interior, we still have a view of the street, the yard next door and the park across the street, providing useful, even essential, information about the world outside. From most angles, the street surface and the passing automobiles are out of sight. Our private space is gracefully framed while the public arena is still visible. A hedge or a pretty bougainvillea arching along the picket fence can also stifle traffic noise; good examples can be found in such heavy traffic areas as St. Armands and along Osprey Avenue.

Could busybodies use this sharing of the public space to pry into our lives? You bet they could, and they should be ashamed of themselves. But the trade-off is maintaining the street as our civic living room, our equivalent of the ancient forum, the place we share in order to know about each other and to protect our interests and values.

A bit of traffic noise is a reasonable price to pay for this kind of arena and for the safety that results from simple awareness of others. As for traffic, remember that it will slow when the street is full of activity.

Don't want to see the life in the street, don't want to hear kids at play or neighbors chatting over the fence? So close the windows, draw the blinds. Or move into a fortress condo, a gated community or into a "ranchette," the catalyst of sprawl. But you'll miss a lot of fun if you do.

Houses behind walls isolate their inhabitants at great cost to the civic experience and the common good. And who ever dared approach one of them to borrow a cup of sugar or return the stray puppy?