OTTAWA -- Ever since there were pirates or wide-eyed children searching for eggs on Easter morning, treasure hunting has been a draw for the adventurous.

The adventure, of course, is in the hunt as much as it is in finding what has been hidden and meant to be found.

Combine that sense of adventure with global positioning technology and a desire to take advantage of the great outdoors, and you have a phenomenon known as geocaching -- and tourism promoters are catching on, hoping to cash in.

Some tourism groups have watched the geocaching trend blossom over the past decade, and are taking advantage of it to attract treasure hunters, and their treasure.

"There are a series of geocaches that have been set up in various locations with the express purpose of bringing people to that area," says John Robb, president of the Ontario Geocaching Association.

The Ottawa Valley Tourist Association, based in Pembroke, Ont., encourages visitors to pack their GPS units and head to Renfrew County, northwest of Ottawa, a region that has become a popular geocaching destination with more than 300 cache sites scattered throughout the area.

Forgot your GPS, or don't have one? No problem. The association, like others, will loan one with payment of a damage deposit.

It has become big business.

"Anybody that does any level of geocaching will, at some point, travel to do geocaching," said Robb.

"And some people take that travel very, very seriously."

Manitoba's Parkland Tourism group is also encouraging geocaching "tourism" adventures, offering tips on how to take part in the recreational activity.

Local groups in the province's Riding Mountain Biosphere Reserve area, encompassing 15 communities surrounding Riding Mountain National Park, place hidden treasures in remote locations, and log the closest GPS co-ordinates.

Many people will go to great lengths to satisfy their quest.

"I know one 'cacher' from Hamilton, Ont., who went to Brazil to find one particular geocache," said Robb, who has himself flown 4,300 kilometres from Toronto just so he could find three particular hidden items in Seattle, Wash.

One of the more popular caching destinations lies just outside of Las Vegas. It's known as the ET Highway. With about 1,500 geocaching sites, the highway serves to attract tourists who want nothing more than to go on the hunt.

Geocaching actually altered the economic makeup of the region. So much so that, when the Nevada Department of Transportation tried in March 2011 to put a stop to the practice, the decision was quickly reversed after local hotel and motel operators warned the loss of business would force them to lay off employees.

It's estimated that about five million people around the world take part in geocaching activities.

And they have roughly two million places in more than 125 countries to choose from to discover hidden treasures. The possibilities appear endless.

While it's difficult to gauge the full economic impact of geocaching on tourism, at least one organization in the United States tried to put a price tag on it.

Operators of the Great Lakes Seaway Trail Geotrail in New York State, with a network of geocaching sites spanning five counties and 500 miles (800 kilometres), estimated last year that the activity raked in one dollar per mile for every participant involved.

The basic idea behind the sport is to locate hidden containers, called geocaches, outdoors and then share your experiences online, either through associations or on a worldwide scale (www.geocaching.com).

Typically, an item is hidden, along with a logbook, an information sheet and sometimes items that can be traded. For example, some caches contain crayons or small toys, typically referred to as swag, that can be taken by the person who finds them, as long as they put something else in its place for others to discover.

Often, those who find items will also leave comments in the logbook. And usually there is a code word on an information sheet that is used to find the website of the group that created the cache, where users can leave other comments and even pictures. That's when the game gets expanded further by a website, which will contain co-ordinates and instructions on how to find the next treasure trove, or a virtual cache.

Multi-caches are very similar to virtual caches with the exception that a traditional cache is hidden at the last stop of the quest. Clues from the virtual caches along the way lead to the final discovery. Like a traditional hunt, clues to locations are key to finding the "treasure."

One of the largest annual geocaching events held in Canada is organized by the Central Ontario Geocachers. This year, hotels in and around Ontario's cottage country are expected to be inundated on June 15 by thousands of the sports enthusiasts for a hunt held at Geneva Park on the shore of Lake Couchiching, about 150 kilometres north of Toronto.