J. called me unexpectedly Saturday with an idea. Last year we’d talked about being more active on our outings, and he’d found something outdoors that interested him — he’d seen an announcement that the toboggan run at Swallow Cliff Woods is to be torn down. Although he never used it, he remembers the run from his childhood and wanted to see it again.

The tearing down of many old buildings in his area upsets J. I understand why, although I point out to him that people are free to do what they like with their property, and nostalgic is not equivalent to historic. Unless a Civil War sniper used the run’s tower as a base to influence a battle outcome, or Abraham Lincoln slept there, it’s just a toboggan run. Even the town in which Swallow Cliff Woods is located can’t save it. I’m sure much of what I loved best about Western New York of the 1960s is gone. I take some comfort in knowing that nothing but time, age, or disease can rob me of my memories.

During the drive, I was reminded of why the south suburbs have grown on me — they are not yet overdeveloped. That this will happen is inevitable, and the signs are there, like a bulldozed field and a developer’s sign across the road from a farmhouse and barn. On the other hand, the Forest Preserve District of Cook County Web site claims that it owns 67,800 acres, or 11 percent of the land in Cook County. Much of that space, like Swallow Cliff Woods, are in the south and southwest suburbs.

It had rained earlier, the sky was overcast, and there was very little spring green in evidence, but for me it’s lovely to be in the woods at any season.

Of course, to get to the woods you must climb the stairs up the hill to the top of the toboggan run. My left knee hated it, my lower back agreed with my knee, and my cardiovascular system let me know that it hadn’t been prepared properly. I took several breathers even as older people passed me. J. beat me to the top and documented my labors in photographs. He wondered about the haul down later; I told him that the descent would be easy.

At the top we spoke to a couple who are about our age. The man recalled using the run as a child in the 1960s, and the quickness and terror of the initial drop. Still panting, I thought about how thousands of children must have climbed the steps effortlessly, over and over.

The man said the reason given for the destruction is cost, although he seemed skeptical. His wife, more practical, pointed out that the Forest Preserve District probably pays expensive insurance premiums. This observation didn’t mollify the men, but they didn’t dispute it. We also discussed the unpredictability of employment, as snow is very irregular in this area.

As we talked, a number of people walked up the steps; a few made repeat trips. We had noticed piles of pebbles and rocks on the stone ledges; the man explained that regulars use the stairs for exercise and track the cumulative number of trips with these rocks. He said that he and his wife are among these regulars, sometimes making five round trips, sometimes three. Often they bring their dog, who is “more interested in the woods than in the stairs. Can’t imagine why.” Later, as we were descending, we observed a determined man with nearly white hair make two round trips without showing any signs of tiring or quitting.

We had some time before sunset, so we walked one-quarter to one-half mile down a wide trail in the woods — wide enough for the horses whose droppings we stepped around. At one point, I heard a dense chorus of chirps that didn’t sound quite like birds or insects; it may have come from frogs, although I don’t know. Alas, I’ve never had much opportunity to develop my woodcraft skills.

During the return, the woods seemed quieter except for the regular roar of jets on their final descent into Midway Airport. In the relative silence, we heard the very loud drilling of a somewhat distant woodpecker. It’s a sound that never fails to thrill me.

J. spotted a tree next to the trail that had two thin trunks of a different bark growing around it. These trunks, which seemed to have clumps of “hair,” looked parasitic to my uneducated eye. I had a strangely emotional reaction to them, a primitive one of horror, as though I were seeing more than a woody plant (or parasite) embracing (or strangling) a tree. I shuddered inwardly while J. took photos for reference in case I wanted to figure out what it is.

In the car while we were debating where to eat, I spotted a sign about a “Lake Katherine Nature Center and Botanic Gardens.” J. backtracked a bit. We walked around this area in the dusk light, observing mallards and a lone swan, probably a trumpeter.

From the neatness of its shores, I judged Lake Katherine to be manmade. The lake, fed by miniature waterfalls, and the surrounding nature preserve consists of 125 acres that began with open space reclaimed by Palos Heights in 1985.

Near the waterfalls, J. noted a sign warning against going onto the little island midstream, which is inhabited by northern watersnakes. While these snakes are not venomous, according to the sign their bite can cause significant bleeding. As if that were not enough to deter the more macho and determined adventurers, the sign writer added that disturbed watersnakes will poop and vomit. J. knew that the triple threat of blood loss and snake poop and vomit was not enough to stop me, but the growing darkness and the unsure footing on small, slippery rocks in the water were. I leaned forward for a while and peered into the misty dimness, willing northern watersnakes to appear. They didn’t.

A peaceful place, Lake Katherine and its grounds are marred only by the electric towers that loom against the southern sky. In the fading light, with mist rising thickly from the water’s surface, I could try to imagine the towers and all that they represent away.

We undid any benefits conferred by the exercise by eating at an Italian family restaurant, beginning with onion rings (my strange craving) and a combination plate of mushrooms and mozzarella and zucchini sticks, a Blue Moon Belgian White and fetuccine alfredo for me, and a soft drink and tortellini for J.

Stuffed (and carrying lots of leftovers), we came here, drank coffee infused with blueberries, and pretended not to ache.