The job listing on Philadelphia's Parks and Recreation website said the position required the ability to lift heavy weights - and the willingness to walk, for miles, through every park in the city, day in and day out, for six months.

To Conor Michaud and Gint Stirbys, that sounded just about perfect.

So for the last two weeks, the two - Michaud, a gym instructor, and Stirbys, a mover - have taken turns hoisting a 50-pound backpack equipped with 15 cameras onto their backs and setting out to digitally document the city's parks.

It's part of a project to photograph the hills and woods and streams and manicured lawns for Google Street View - and Philadelphia is the first city to do it.

City officials hope the project will not only draw out-of-town visitors to the parks but encourage Philadelphians to better explore their own backyard.

"There are so many treasures in the parks that people never get to see," Tim Clair, interim executive director of the Fairmount Park Conservancy, said Monday at a news conference near Belmont Mansion. He was flanked by Stirbys and Michaud, who sported the Google Trekker backpack, with its cameras mounted on a green sphere attached to a pole that extends about two feet above his head.

The contraption is like the one Google mounts atop cars for its Street View project. Using a Trekker backpack last year, someone mapped the Grand Canyon. And an intrepid employee at a suburban parks department has taken one deep into Bucks County.

But Philadelphia is the first city to try to catalog the trails in all of its parks - about 200 miles of them - on Street View.

"It's really aggressive, what we're trying," said John Piller, special project manager for the city's Parks and Recreation Department.

The department got the idea about a year ago, when an employee heard about the Trekker backpacks at a tech conference. Google provided one to the city free, and Stirbys and Michaud earn $15 an hour lugging it through the parks each day.

They start their days around 9 a.m. and end around 3 p.m. in order to capture the parks in the brightest sunlight. One wears the backpack as the other walks ahead on the trail, picking up trash and debris so the parks look their best for Google. The cameras take a panoramic shot every three seconds.

Before lunch on Monday, the pair - both experienced hikers - had covered five miles and hoped to do more before the light ran out. They have hit 11 parks since May 2, mostly smaller ones in South Philadelphia.

"It's a nice little meditative experience," Stirbys said. The native Philadelphian has spent the last two weeks hiking through parks he'd never heard of before he was hired - such as Lardner's Point, just south of the Tacony-Palmyra Bridge.

Nora Dougherty, a geographic information systems specialist for the parks department, has mapped out a schedule of places to shoot over the next six months. Weather can set back filming, she said, as can construction or a shaggy lawn.

Stirbys and Michaud have until Nov. 1 to work their way through all the parks before Google asks for its Trekker back.

"We have plenty of time," Michaud said.

Peering at a map of the parks that have been photographed and all that have yet to be, Piller said with a laugh, "They're going to be walking their butts off."