This is one cache in a series of 10 being placed in honour of the Dewey Decimal System. (They are not being released in numerical order.) You can take the girl out of the library, but you can't take the library out of the girl! Each cache has a theme, which is reflected in the Dewey number it has been given. I am not assigning cutter numbers or subject headings. ;)
305 is the Dewey number for "Social sciences, sociology & anthropology - Groups of people". It's representative of our choice of hobby (at least when it comes to events!) more than this particular location. That said, you will find the people here are generally quick to smile and very friendly.
When I started this addiction, there were caches all around the lake. Several have now been archived, so I would like to start bringing people back to this wonderful urban oasis. If you enjoy bird watching, there are often great opportunities here, for common sights like Canada Geese and Mallards to Red-Necked Grebes, Common Golden Eye, and even occasional pelicans and cormorants!
You will need to be a bit stealthy, but as long as you don't make it too obvious, people will just think you are enjoying the sights. A camera or small children would be good "cover" here. This one may well get snowed in in the winter, unless you have good boots and possibly a shovel!
PLEASE put it back exactly as you found it - higher or to the sides and it will be too easy to spot for muggles.