Here's what you need:
- 1 pop up sprinkler head
- A 35mm film canister
- A small spade
- Bison tube
- Toothpick, thin Dowel Rod, or popsicle stick
The best sprinkler head to get is one of those common round black ones you can find in most Gardening or Hardware stores. For the spade...well that will depend on the location you choose to place it at. We'll discuss that after looking at the build.
The first thing you will need to do is unscrew the top of the sprinkler head, marked in the image to the left. Once open, look carefully at the guts. Sometimes there is a hollow piece running the length of the sprinkler that could easily hold a rolled up logsheet. If not, just pull out everything, leaving the sprinkler casing and lid.
Next, get your logsheet ready. The simple way is just to get a standard micro logsheet. You can staple a few sheets together if you want to allow more finds between log refills. Now if there is a hollow piece inside, you can slide the logsheet into there. If this is an option, I recommend attaching something at the center of the roll that people can grip to pull the rolled up logsheet out. A popsicle stick or thin dowel rod works great.
If there is not a hollow piece inside, then grab a micro container like a 35mm film canister, bison tube, etc. Make sure it will fit inside, then add the logsheet and then toss the container inside the sprinkler head.
Once you have everything inside, just seal it up. Now you need to find a location for it. This is where this one can be tricky. If you pick a spot with mulch, there's a chance the mulch is deep enough that you can just clear out a hole, place the sprinkler inside, and position the mulch around it to fill gaps. You could also find a small bush, insert the sprinkler head through some branches, and cover the top with a leaf or two. But sometimes, you might need to dig a small hole. If you have exhausted other options and decided on digging, make sure you have permission from the landowner if it isn't on your property. This is especially true at parks. If a muggle sees you pulling up a spinkler head, they might get suspicious enough to report it. You'll want the parks department to be aware of it.
To the right is an example of how to hide it to blend in. Notice that unless you were looking for the cache, and even if you are looking for it, this sprinkler head looks like it blends in rather well. You might not even realize it's not real unless comparing it to surrounding sprinkler heads (if there are any).
As you can see, this cache is a great example of concealing a cache out in the open. It has become more common in the last two - three years, and some Geocaching stores will even sell ready to go versions of this. The downside is blending it in. Many parks and homes now have these pop-up sprinklers installed. If you know what location you are aiming to place it, you can try to match the design as closely as possible to better blend it in so it doesn't stand out. Imagine an all black sprinkler head as the real sprinklers, then having the cache in one that has a bright white stripe around the lid. An observant person might notice that.
Also, if you look at the picture of the cache surrounded by mulch, you'll notice the white base, a piece not seen in the first image. An additional way to set this into the ground is to use a piece of PVC pipe that snuggly fits the sprinkler head. Then, when you set up the hole for the cache container, you can place the PVC pipe in the hole. Now, when the cache is retrieved and then put back, it will quickly slide into place. No need to make sure dirt or mulch doesn't fall into the hole and force finders to redig them back out.
Now we have one more photo to show you. In this case, it's an example of a homemade logsheet. A longer piece of paper, likely from a calculator printer roll, has been rolled up with a small toothpick in the center. The toothpick is taped to the printer roll. Just twist to tighten the paper up on the toothpick and then pull down. The housing is a small plastic sleeve glued inside a small piece of PVC pipe with a Geocaching logo taped to the side. A rubber plug is at the top end to help seal that side. And this all fits nicely into the sprinkler head. Even though the logsheet isn't in a baggie, it has remained quite dry.
Like I said, a rather simple hide to build, not to bad to place, and great for concealment in plain view. And this design works with any type of cache: traditional, multi, or puzzle.