Geocaching (pronounced /ˈjēōˌkaSHiNG/) is a 21st century version of hide and seek; a kind of hi-tech scavenger hunt. 

Geocaches are listed on several websites.

The largest listing is hosted by the US-based company Groundspeak www.geocaching.com

Other lists include:

The first geocache in Australia was placed by Paul Edwards in Lane Cove National Park on 18 May 2000. Although the geocache was removed a year later, you can still visit the location and log a find as it is now a virtual.

Lane Cove (GC3E) by Paul Edwards

The next geocache in New South Wales was placed in Garigal National Park, near St Ives on 2 September 2000 — R&R (GC52) by Richard Ames (archived)

Three more geocaches were hidden in New South Wales in 2000:

• Frying Pan (GCF1) by Dave Walmsley in Chichester State Forest near Dungog
• Australia's Highest (GCF7) by Roland Turner, Anand Kumria, James Davidson in Kosciuszko National Park
• East of Ulan (GC154) by Alex near Murragamba, Central Tablelands (archived)

In the first few years of geocaching you could count the number of fellow geocachers on one hand, and most of them you only knew online. It wasn’t unusual to have to spend a good part of a day searching for one of your closest unfound geocaches and locationless and virtual geocaches were still part of the game.

Then, in the second week of 2004 a new type of geocache appeared — the EarthCache. At the time it was listed as a virtual geocache, the first one being Earthcache I - a simple geology tour of Wasp Head.

It took me a few months to find the time to head down to the south coast of New South Wales and find it, but in the meantime a second EarthCache close to work appeared - Earthcache II - the geology of WoolShed Creek, NSW. Not surprisingly I got first to find.

Paul Edwards (kerravon) hid Australia's first geocache on 18 May 2000. To mark the 10 year anniversary, Paul tells how he become Australia's first geocacher.

At the recent 10 Years! event, I kept getting asked "how did you find out about geocaching?"

For me this is a strange question. It's a bit like asking someone "how did you know you were in a car crash?"

It's not that I "found out", it's more that it was "just there". I happened to be part of a community in which someone announced what use he had personally made of the switching off of Selective Availability (SA).

Each geocache is different, and so is each geocache hunt. There are many things each geocacher should take into consideration.

Before you start walking

Prepare! Use aids such as Google Earth, Whereis, and street directories to get a clear idea of not just where the cache is hidden, but what is in the area and how to get there. If the cache well away from roads, other aids like paper topographic maps and Open Street Map should be consulted to identify which tracks to take.

Check the cache attributes read the description and know your limitations. Some need kayaking, swimming, tree climbing or abseiling. If it looks too risky, go for another one instead. 

Dress appropriately for the conditions and location. Think long sleeves, long pants, hats, sunscreen and perhaps even gloves. Take appropriate equipment for your cache hunt, particularly if it involves a hike or long walk. Do you have water, charged phones, torches and batteries?  

Most importantly, let someone know where you're going and when you'll be back.

When you plan on heading to a geocaching event, it's not unusual to find a few geocaches before, during or after the event.

It's a great way to visit a new area and make the most of your trip.

Here we provide you with a tip on how to set up a pocket query centred on the geocaching event.

Puzzle caches are a great alternative to traditional geocache. But for many geocachers they are too difficult or require too much effort.

This page has been written to give you some tips on how to solve those puzzle caches that might currently be beyond your reach.

It covers what to look for when solving a puzzle cache, some of the clever techniques used to hide clues and how to confirm you're on the right track.

This session was originally presented at the Geocaching NSW 2010 AGM event by founding president, Darren Osborne.

Five tips of geocaching

1 - don’t follow the arrow, follow the trail

Your GPSr will always show where they cache is in a straight line.

If you’re walking through the bush, there’s a fair chance that the track will not be straight. In fact sometimes the track may take you away from the cache.

Don’t be tempted to bush bash and head straight for it. You may find that the track eventually finds its way to the cache.

Not following the track can not only take you longer, as you travel through thick bush, you could also damage wildlife.

2 – plan your cache hunt

Some caches are straight forward. Many urban caches are not hard to find and typically rely more on cunning placement, than a challenging walk.

Caches in bushland or remote regions should be studied in detail to identify where you should park and what path to follow.

Google Earth or Google Maps are a great place to start. The satellite/aerial images allow you to identify the lay of the land, things such as roads, parkland and bush.

Topographic maps and street directories are also very useful.

3 - take a backpack

No matter where you go, a backpack is handy to take geocaching.

In the summer, you should carry sunscreen, insect repellant, a hat and plenty of water. In the winter, a rain jacket, beanie and even an umbrella are handy. I also pack a first aid kit, spare pens and logbooks, food and gloves. Gloves are handy not only for bush caches where you might be wary of snakes, ticks and spiders, but also with urban caches, where you have to avoid spiders (again), rubbish and occasionally syringes.

4 – respect the environment

Most of the time you know where to find the cache, or where it should be.

If you need to conduct a more detailed search of the area make sure you replace any rocks, logs, branches and even leaf litter. You could be disturbing someone’s home. 

Sometimes the geocache is close to the corner of a garden bed or on the outer edge of clump of shrubs.

Sometimes the cache hider likes to make it a little difficult to find. This doesn’t give you an excuse to tear the place apart. If you can’t find it, then you may have to walk away and try again another time.

Hiders should also be aware that by placing a cache it will encourage a greater number of people to explore that area, typically in a 20 metre radius. Consider what impact this will have on the environment.

Also remember tip one about paths and tracks. Park rangers frown upon the creation of new paths, particularly through sensitive areas.

Ensure that your cache is far enough from muggle zones but don’t venture too far into unmarked areas.

5 – respect the feeling of your fellow geocachers.

The Internet is a very impersonal medium. Sacracism loses its humorous nature on the ‘net and its very easy to offend someone, when you thought you were being funny.

Remember that your logs also appear in the public domain. If you are unhappy with experience at a cache be diplomatic and fair or contact the owner privately.

If you find a particular geocacher’s style of geocaches not to your liking consider adding them to your ignore list and avoid confrontation.

Remember, there are many types of geocachers each with their own likes and dislikes. What you consider to be "geo-trash" is another person’s "geo-treasure".