Seriously, No Swimming Here!
Apparently, there have been quite a few issue with people swimming in this field.
However, since they put up this “No Swimming” sign, the number of swimmers found has been drastically reduced.
Just goes to show that sometimes all you need is a good sign… 
(link)
By Mui Mui on 07-01-2009
Comment by Loren Pechtel
January 9th, 2009 at 9:34 am
Note that the ground is a lot lower behind the sign. It could very well be a seasonal lake.
Comment by OllyBob
January 13th, 2009 at 3:49 pm
think you missed the joke.
Comment by Sabrina
June 10th, 2009 at 6:51 am
No water, no swimming. I don't think the sign has much to do with it. This reminds me of a good blonde joke.