Make sure the parks you hunt are old enough to have silver. That park dose not look 30 years old. I don't know maybe it is 100 years old it just looks new. How close you stay with your children is mostly up to you. I hope you can find some silver together soon.
It's a lot older than it looks. the oldest confirmed date I could come with was when the little zoo was installed in 1901. the picture is of the same park from the early 1900's