N 43° 41.160 W 079° 22.120

Latitude and Longitude are plotted in terms of degrees, minutes, and seconds. This location happens to be in the vicinity of the Don Valley Brick Works. Why is this exact location significant? Because it is the location of a geocache. Geocaching is a worldwide treasure hunt game. It utilizes the global positioning satellite (GPS) system setup by the US military during the cold war. In the year 2000, they allowed access to the general public. Shortly afterwards geocaching was invented.

To play it you need a GPS locator device (see picture). These devices are moderately expensive ranging from $100-300 per unit. My Explorist 100 is near the lower end. When you turn it on it immediately starts to search for satellites overhead. This process takes about two minutes. Once a position has been fixed, it displays the latitude and longitude and constantly updates it as you move around. Depending on the unit it can be accurate to about 3 metres.


GPS Locator device

In the geocaching game you can be either a Cacher or a Seeker. If you are a Cacher, you obtain a small container such as a plastic Tupperware container that is water proof and place in it a logbook, a pencil, and a collection of small trinkets - just like a treasure chest! You then place this anywhere you like, in the city, in a park, or out in the country. With your GPS locator you determine its location. You then post this information on the geocache website. You can make it easy or hard to find.


Contents of another Don Valley cache. This one is contained in a modified ammo box, specially sold by the Geocache suppliers.


Being a Seeker is the best part of the game. You go to the website and note down locations of caches in your area and then go out and try to find them. Uncovering a geocache is always enjoyable, it's like opening up a present under the Christmas tree.

When you find the cache, you open the container. You're supposed to write your name and date in the logbook. You can take one of the trinkets as a memento of your find. Some people also put more stuff back into the container so the contents are always changing. However nothing valuable is ever stored in a cache. We took a fridge magnet and left a breath mint.


My friend holds the container and our loot!

We also took a geocoin (in her left hand). This is a special geocache item. Each coin is individually numbered. The first person puts it into a cache. Someone else retrieves it and then moves it to another cache somewhere else. You then post a separate log of this on the geocoin website and then you can see where this coin has been. Some coins travel all around the world. This coin, number 3007 has moved around the Toronto area and once to Algonquin Park.

There are over 100 geocaches in the Toronto area and about a dozen in the Lower Don. It took me a couple of tries to find the Brick Works cache because it located in a area of deep undergrowth. At some point I will become a cacher and place them in interesting places in the valley.