THE IDEA SPRANG full-blown from the centerfold of "Pigs Say Oink," which I found myself reading to my 23-month-old daughter Sunday morning. As a steamy haze hung outside the house and the air conditioner purred inside, it became obvious that Sunday was not a good day to go to the pool, and it also became obvious that I'd better think of something quickly or else I might find myself reading "Pigs Say Oink" for the rest of the day. Suddenly, we turned the page and came upon a wonderful display of animals at a zoo.

"I have an idea," I announced brightly to my husband, whose idea of the perfect Sunday is to be able to read the papers without having somebody come up with an idea.

"What?" he finally replied.

"Let's go to the zoo today." The logistics were perfect. My oldest son had spent the night at a friend's house, which was five minutes away from the zoo. We could pick him up and then take the younger children to the zoo.

By 1 o'clock we were packed into the car: Two adults, one toddler and her stroller, the five-year-old and his friend. Getting in town should have been our first clue that this was not going to be easy. We played Detour Roulette, and on the assumption that Chain Bridge was closed from Virginia to D.C. on Sunday, we took Key Bridge. Not only was it the longer way into town, it was the wrong way.

We picked up our oldest son and then went off in search of Connecticut Avenue and the National Zoo, which we finally located after a shortcut took us 20 minutes out of our way. "I didn't want to bring this up before," said my husband dourly, eyeing the traffic jam near the entrance to the zoo, "but has it occurred to you that we might not be able to park?"

Well, it had occurred to me, right as we drove past the home of friends who used to complain that they couldn't park on Sundays because zoo-goers took up all their parking spaces. It didn't seem like the right time to bring up that anecdote, however.

I find that when my family adventures are on the brink of turning into fiascos, it is very helpful to continue thinking positively. "I shouldn't think we'd have a problem," I said. "Look at all those cars coming out of there." As we finally turned into the zoo, I searched the faces of the people in the cars coming out. Were they coming out after a lovely day at the zoo or were they angrily heading out into the city in a final search for parking spaces?

You can, of course, guess the answer.

Not far into the parking area, we came upon the first of several lots whose entrances greeted us with blazing red lights: "Lot Full Closed." We followed the caravan of cars until we started passing lots with empty spaces in them. But they, too, had signs saying they were full and closed, a fact we pointed out to a policewoman directing traffic. "You can't stop here," she said, waving us on.

"But there are empty spaces in there. Why can't we park there?" we asked.

"You can't go in as long as the signs say the lot is full," she said.

We said that didn't make any sense.

She blew her whistle and announced that the lot wasn't her problem, that her job was to keep traffic moving.

"You got an easy job," snarled my husband. And with that we followed the caravan past more lots with "closed" signs on them until we found ourselves all the way out of the zoo. The streets in front of the apartment buildings on the other side of the zoo were just as lined with parked cars as the streets off Connecticut Avenue. Things were not going well. The children were not the only people in the car making sounds that can't be repeated in a newspaper.

We turned around and threaded our way back into the zoo in one last attempt to find a legal parking space. The results were the same. By the time we got to the panda exhibit the dilemma was clear: We could go home or my husband could let us off and park somewhere outside the zoo and hope to find us again someday. We looked at expectant faces in the car. We got out. My husband drove off. Our tribulations had just begun.

A logical byproduct of the fact that we couldn't find a parking space was that the zoo was terribly crowded. And a logical byproduct of the steamingly hot days was that the animals, apparently endowed with better sense than people, stayed inside their houses. We did see the seals, but the polar bears were nowhere to be found. The snack bars around the zoo ran out of things to drink and their rainbow snow cones don't do much more than attract bees, which were everywhere. And the reptile exhibit, which for reasons I prefer not to contemplate, was the one thing my five-year-old was dying to see, is still closed until this fall. Thirsty, hot, and weary, we finally trudged out of the zoo onto Connecticut Avenue and began the long walk toward the car, which by then was adorned with a $10 parking ticket.

I distributed sips of 7-Up from a small thermos, feeling like I'd just led my family across the Sahara for absolutely no good reason on earth.

"I guess that wasn't such a good idea after all," I said on the way home. (A meek apology is sometimes the best defense.)

But the voices of my husband and oldest son were unforgiving. "Let's not talk about it," they said, in steely unison. "Let's just forget it."

I tried a joke. "Next week, I thought we could. . ."