You are looking for a smallish camoflaged glass container.
The cache contains a paper log, pencil and few little treats for any kids to take as a monento of the find, please only for the littlies and just one per child as there was only room for a few in the container.
It might be a good idea to take a pen with you just incase the point gets broken off the pencil, or a pocket knife to sharpen it if required.
There is also a FTF badge for the lucky first person there to keep. 
It is best to approach this cache from pathway alongside the creek. Please ensure the lid on the cach is secure so it stays dry and put the it back out of site as found otherwise there will be no challenge for the next explorers.
At certain times of the year this area can be very popular so beware of muggles who might follow you to see what you are up to.
Happy hunting !