Alek Joyce, geocaching enthusiast, has searched the Colorado wilderness to find caches, tech-speak for what are basically hidden treasures.

But last Tuesday, the Central Junior High School student’s latest geocaching adventure took him to an urban setting: downtown Lawrence. Outside Central National Bank, people are milling about, perspiring in the aftermath of a surprise thunderstorm; drivers are trolling Massachusetts for parking spots.

Alek stands on the crowded sidewalk, examining the small yellow GPS unit in his hands. It gives him a latitude and longitude for a cache that should be within about 20 feet of where he’s standing.

“We’re close,” he announces.

Geocaching is a hobby for outdoor enthusiasts that has evolved into a worldwide game: You hide a cache, typically a small container that can be well-concealed in public places, then use a global positioning system unit to determine its latitude and longitude coordinates and post the location online for other geocaching fans to track down.

A 66046 zip code search at geocaching.com finds several locations for hidden caches: Veterans Park, Clinton State Park, Dad Perry Park.

And Central National Bank.

Alek Joyce, a Central Junior High School eighth-grader, uses a handheld GPS unit to find a geocaching site near Eighth and Massachusetts streets.

Alek walks east on Eighth Street toward Henry’s; he abruptly retreats. “Too far,” he says.

He frequently looks down at the GPS unit as he walks west, crossing Massachusetts Street. He stops outside the Round Corner Drug Store.

“Too far,” he says again. He shakes his head.

Alek walks back toward the bank.

The gear

A GPS unit is an electronic device that tells you approximately where you are on the planet; it can cost $100 or more, comparable to buying a PlayStation console, except geocaching is a far more physically active hobby.

And that’s an aspect of the game that appeals to Kansas University senior Chris Jones, who has found nearly 140 caches statewide in the last year.

“It’s an excuse to be outdoors,” Jones says. “It’s fun. It’s a reason to hike and explore for a while.”

Jones says he didn’t spend much on his GPS unit, though it can download notes from the Web, eliminating the need to type in a location that reads like: N 38° 57.254 W 095° 16.425.

Lawrence eighth-grader Alek Joyce, aka kidconverse, leaves an old Converse shoe with a travel bug at a cache he found in Avon, Colo. The dog tag has a serial number that can be entered on the geocache Web site. People who find the cache can take Alek's travel bug and plant it at new sites, allowing him to track his shoe around the world.

“Enter one wrong number,” Jones says, “and you could be off a hundred miles.”

Alek’s GPS unit was a gift.

“My brother got Alek the GPS unit for Christmas two years ago,” says Holli Joyce, Alek’s mother. “Alek’s the kind of kid who would get on the Internet right away and really get into it.

“It’s been fun when we travel,” she says. “Whether we go to Manhattan or out of state, he’ll take it with him. It’s fun for the whole family.”

No place to hide

Alek studies the north wall of the bank. There doesn’t seem to be a good hiding spot for a 3-by-1-inch box as promised at geocaching.com. A perusal underneath a blue canopy fails to yield any clues.

The bank depository, however, looks promising. Alek swings it open, peeks into the mechanism. There is nothing behind it, nor does it look like a good place to stick your hand.

“I’d better look at the clue,” he finally says.

The treasures

Alek’s printout from geocaching.com has the cache’s coordinates and an encrypted code, complete with legend, for hints if a tracker cannot find the cache.

And finding what’s inside the cache is part of the fun; whoever plants it may leave small toys, trinkets, a log book – even money.

“The caches always have more than one thing inside,” Alek says. “I’ve found some cool things. Someone left a handgun lock once.”

Alek Joyce plugs latitude and longitude coordinates into his handheld GPS unit to pinpoint the exact location of cache sites. Sometimes a treasure awaits him.

Not a handgun, though: Alek says it’s understood that weapons, alcohol and food aren’t to be left for explorers. (Anything edible will draw animals.)

“People leave funky little things,” he says. “They’ll leave personalized stuff with a Jayhawk. I found a wooden alphabet block with the family’s name on it.”

“Don’t forget the banana water gun,” Holli adds.

If you take something from a cache, you should leave something in its place, according to geocaching.com’s FAQ, which is like an etiquette guide to an online community that has registered more than 202,000 caches hidden in 218 countries.

Among items Alek leaves behind are magnets and old Converse shoes, fitting for his online user name, kidconverse.

Alek not only searches for caches, but he’s also planted his own, listed online as StoneFree TB Depot. It’s in northwest Lawrence, he says, near the Hy-Vee Food & Drug Store on Sixth Street. And quite a few people have tracked it down.

“We get two messages a day – two messages on average – through the Web site with people telling us they’ve found it,” Holli says.

Ask a teller

Alek finishes deciphering the clue to the Central National Bank cache.

Alek Joyce leaves behind a Converse shoe at an Avon, Colo., cache he's tracked down. Geocaching enthusiasts can take a treasure from a cache when they find a site, but it's considered good etiquette to leave something in its place.

“Ask inside,” he reads aloud. He heads indoors to talk with a teller.

Jones, a psychology major, can relate to the difficulty of Alek’s hunt.

“I’ve been to that site,” he says. “I actually showed up at (the bank) to be the first to find it after it was posted. Somebody else was there, too. I was the second to find it.”

Alek returns and heads back to the depository. He then notices the silver drawer marked “FORMS.”

He slides it open and takes one of the bank slips. While his search fails to yield any other treasures, Alek seems happy. He can go online and obtain a credit for finding the site.

“I’ve found less than 10 in the Lawrence area,” he says later. “I can’t take part in it all of the time because after school is pretty busy.”

More for grown-ups

While geocaching seems like a kid-friendly activity, Alek says other online users tend to be adults.

“Scout leaders will do it. Couples and families do it,” he says.

Jones, who also likes mountain biking and kayaking, says he’s brought friends on searches a few times but often goes alone.

“It’s usually older people looking for a hobby,” he says of fellow geocaching enthusiasts.

And though Alek also searches alone, he’s pleased with his find at the bank.

“It’s not so much a teenager-y thing to do,” he says, “but it’s good for all ages.”