The back of the volunteer badge dangling around my neck listed a number of instructions. It told me to wear closed-toe shoes and protective gloves, and avoid handling hazardous material, such as broken glass, needles and horse patties. I should complete my litter-picking route within an hour and return the equipment by 4:30 p.m. And I should never answer any questions from the public, but direct them instead to a park employee or a visitor center.

Abiding by the rules, I eventually stopped asking myself where I was. Because beyond the obvious — You Are Here in Central Park — my exact location among the 843 acres, dozens of statues and sculptures, seven bodies of water and seven meadows was elusive. But then again, the park's creators did intend for visitors to lose themselves in the inner-oasis. So I walked right past the man in the Central Park Conservancy T-shirt, my laminated card bouncing in defiance.

The iconic New York park is no mere green smudge on Manhattan's face. It's an island on an island, a self-sustaining microcosm with its own ecosystem and personality (multiple, in fact).

"It's so big, it scares me," said a staff member at the Kerbs Memorial Boathouse, which rents model sailboats. "I got lost on July Fourth and had to call a cab."

But that's an essential part of the anti-urban adventure: to get lost and see what you can find.

In May, I accepted the challenge and locked myself inside the park's borders. For nearly two days, I relied on it to fill my basic needs (food, drink, exercise, penguins) and more esoteric cravings (gondola ride, film sites). Not once did I look for an escape hatch, except at night — getting arrested for sleeping in the park would cut into my daytime exploration. If only the park had an on-site jail.

The Central Park Conservancy, which manages the park under a contract with the city, provides information on sights and daily events. The calendar listing for the last weekend in July, for example, includes a dozen activities, including a walk from Harlem Meer to the Pool, the Iconic Views of Central Park Tour and a performance by an eco-troupe.

The nonprofit group also offers downloadable maps for self-guided walking tours (North End, Mid-Park, South End, Woodland, Tree) and an audio guide featuring celebrity narrators: Whoopi Goldberg on the Alice in Wonderland statue, Jerry Seinfeld on the Mall, former mayor Michael Bloomberg on tree care.

Individual attractions, such as the Central Park Zoo and the Loeb Boathouse, also give a loud shout-out to their own diversions, including animal feedings and gondola rides. Finally, outside operators run theme tours, covering movie and TV sites and arts and architecture. The cresting river of options is exhilarating — and overwhelming.

At Belvedere Castle, I asked a visitor center volunteer whether someone with no dependents and no shares in Apple could engage in every activity. His one-word response: "Impossible."

And with that, I surrendered to the inevitable: I couldn't do it all, or even half. Maybe a sixteenth.

The main draws — the zoo, the nature sanctuary, the bandshell, the literary walk, etc. — congregate in the southern portion of the park. Most visitors barely tread beyond the castle, which perches nobly on a hill slightly above the 79th Street Traverse.

The visitor center also dispenses wildlife kits (I skipped the children's activity book but grabbed the binoculars and field guide on birds) and signs up volunteers for trash pickup. In 1980, the conservancy took over park maintenance, and it depends on donations (which make up 75 percent of the $58 million budget) and hundreds of volunteers to keep the bucolic retreat at its tidiest. The park needs me and you as much as we need it.

The "Pitch In, Pick Up" program requires little effort. I was already walking around the park and occasionally looking down to avoid tripping, so why not retrieve trash along the way?

I set out for the zoo to catch the afternoon sea lion and penguin feedings, my plastic gripper poised for duty.

Three sea lions streaked like dark lightning bolts underwater, then leapt onto a pile of boulders on the edge of the pool. They vogued for the spectators before splashing back into their micro-ocean.

I didn't have time to wait for an encore performance, because the penguin lunch bell was about to ring. I entered the chilly Arctic Polar chamber and pressed my face against the glass tank filled with Gentoo, chinstrap, rockhopper and king penguins. It was the ultimate penguin party, formal attire required.

The zookeeper appeared behind the misty glass, dressed as if she were going on an Arctic research expedition. She fed each bird, often shoving a fish twice the size of the bird's head into its mouth.

A few of the penguins didn't leave their nook for snack time. A volunteer explained that they were pregnant and bound to their nests. When I asked for suggestions on other calendar-cute baby animals, she recommended the red pandas, the cranes and the mongoose. Then she noticed my paraphernalia and said, "Thank you for conserving the park."

On the return walk to Belvedere Castle, I followed a corkscrew route through the densely forested and nobby Ramble. I popped out of the trees to discover a turtle, which I did not grab, and a cardboard box, which I did. Steps from the castle, a family waved me over to a stone wall and said, "There's a popsicle stick."