The above coordinates take you to a place you cannot actually reach so… you will need to make an ‘educated guess’ as to where your hunt begins. As originally designed, the starting spot was a fountain in the middle of the pond. I don't think that fountain functions anymore but you don't actually need to know that to find the cache.
To locate the cache, go 290 feet at 290 degrees. The container is hidden in a natural way. Don't bother looking under any un-natural objects that may be in the area.
There is visitor parking close by. Please respect the parking rules of this institution. No night hunts! You should have the place to yourself on the weekends. Have fun!