Unlock the Fields

I noticed a single lock on a fence as I walked past my local playing fields & I thought why would a person do this? The last time I saw locks on a fence was when I was in Paris last February. I believe it was called 'The Lover's Bridge' which goes over the Seine River.
Maybe it was just this person's way of wanting to spread his/her love for the Gold Coast! I might put a lock of that fence tomorrow...